Near-Optimal Detection in MIMO Systems using Gibbs Sampling (2009)
Hansen, Morten, Hassibi, Babak, Dimakis, Alexandros G., Xu, Weiyu
In this paper we study a Markov Chain Monte Carlo (MCMC) Gibbs sampler for solving the integer least-squares problem. In digital communication the problem is equivalent to performing Maximum...
Violating the Ingleton Inequality with Finite Groups (2009)
It is well known that there is a one-to-one correspondence between the entropy vector of a collection of n random variables and a certain group-characterizable vector obtained from a finite group and...
Performance of sphere decoding of block codes (2009)
El-Khamy, Mostafa, Vikalo, Haris, Hassibi, Babak, McEliece, Robert J.
A sphere decoder searches for the closest lattice point within a certain search radius. The search radius provides a tradeoff between performance and complexity. We focus on analyzing the performance...
Efficient and Robust Compressed Sensing Using Optimized Expander Graphs (2009)
Jafarpour, Sina, Xu, Weiyu, Hassibi, Babak, Calderbank, Robert
Expander graphs have been recently proposed to construct efficient compressed sensing algorithms. In particular, it has been shown that any n-dimensional vector that is k-sparse can be fully...
Achievable Throughput in Two-Scale Wireless Networks (2009)
Gowaikar, Radhika, Hassibi, Babak
We propose a new model of wireless networks which we refer to as "two-scale networks." At a local scale, characterised by nodes being within a distance r, channel strengths are drawn independently...
Data Transmission Over Networks for Estimation and Control (2009)
Gupta, Vijay, Dana, Amir F., Hespanha, Joao P., Murray, Richard M., Hassibi, Babak
We consider the problem of controlling a linear time invariant process when the controller is located at a location remote from where the sensor measurements are being generated. The communication...
On the Reconstruction of Block-Sparse Signals With an Optimal Number of Measurements (2009)
Stojnic, Mihailo, Parvaresh, Farzad, Hassibi, Babak
Let A be an M by N matrix (M < N) which is an instance of a real random Gaussian ensemble. In compressed sensing we are interested in finding the sparsest solution to the system of equations A x = y...
Benjamin Recht, Weiyu Xu, Babak Hassibi
Abstract — Minimizing the rank of a matrix subject to constraints is a challenging is a challenging problem that arises in many control applications including controller design, realization theory...
Peak Power Reduction of OFDM Signals with Sign Adjustment (2009)
Sharif, Masoud, Tarokh, Vahid, Hassibi, Babak
It has recently been shown that significant reduction in the peak to mean envelope power (PMEPR) can be obtained by altering the sign of each subcarrier in a multicarrier system with n subcarriers....
Xu, Weiyu, Khajehnejad, M. Amin, Avestimehr, Salman, Hassibi, Babak
It is now well understood that $\ell_1$ minimization algorithm is able to recover sparse signals from incomplete measurements [2], [1], [3] and sharp recoverable sparsity thresholds have also been...
Capacity region of the deterministic multi-pair bi-directional relay network (2009)
Avestimehr, Salman, Khajehnejad, Amin, Sezgin, Aydin, Hassibi, Babak
In this paper we study the capacity region of the multi-pair bidirectional (or two-way) wireless relay network, in which a relay node facilitates the communication between multiple pairs of users....
Sparse Recovery of Positive Signals with Minimal Expansion (2009)
Khajehnejad, M. Amin, Dimakis, Alexandros G., Xu, Weiyu, Hassibi, Babak
We investigate the sparse recovery problem of reconstructing a high-dimensional non-negative sparse vector from lower dimensional linear measurements. While much work has focused on dense measurement...
Peak to Average Power Reduction Using Amplitude and Sign Adjustment (2009)
Masoud Sharif, Cedric Florens, Maryam Fazel, Babak Hassibi
Abstract — In this paper, we propose a method to reduce the peak to mean envelope power ratio (PMEPR) of multicarrier signals by modifying the constellation. For MPSK constellations, we minimize...
Weighted $\ell_1$ Minimization for Sparse Recovery with Prior Information (2009)
Khajehnejad, M. Amin, Xu, Weiyu, Avestimehr, Salman, Hassibi, Babak
In this paper we study the compressed sensing problem of recovering a sparse signal from a system of underdetermined linear equations when we have prior information about the probability of each...
Real-time DNA microarray analysis (2009)
Hassibi, Arjang, Vikalo, Haris, Riechmann, José Luis, Hassibi, Babak
We present a quantification method for affinity-based DNA microarrays which is based on the real-time measurements of hybridization kinetics. This method, i.e. real-time DNA microarrays, enhances the...
Data Transmission over Networks for Estimation and Control (2008)
Vijay Gupta, Amir F. Dana, Student Member, João P. Hespanha, Richard M. Murray, Babak Hassibi, ...
We consider the problem of controlling a linear time invariant process when the controller is located at a location remote from where the sensor measurements are being generated. The communication...
Scaling laws of multiple antenna group-broadcast channels (2008)
Al-Naffouri, Tareq Y., Dana, Antir F., Hassibi, Babak
Broadcast (or point to multipoint) communication has attracted a lot of research recently. In this paper, we consider the group broadcast channel where the users' pool is divided into groups, each of...
Differentiated rate scheduling for the down-link of cellular systems (2008)
Dana, Amir F., Sharif, Masoud, Vakili, Ali, Hassibi, Babak
We consider the problem of differentiated rate scheduling for the downlink (i.e., multi-antenna broadcast channel), in the sense that the rates required by different users must satisfy certain...
Recht, Benjamin, Xu, Weiyu, Hassibi, Babak
Minimizing the rank of a matrix subject to constraints is a challenging problem that arises in many applications in control theory, machine learning, and discrete geometry. This class of optimization...
The secrecy capacity of the MIMO wiretap channel (2008)
Oggier, Frédérique, Hassibi, Babak
We consider the MIMO wiretap channel, that is a MIMO broadcast channel where the transmitter sends some confidential information to one user which is a legitimate receiver, while the other user is an...
An Algebraic Coding Scheme for Wireless Relay Networks With Multiple-Antenna Nodes (2008)
Oggier, Frédérique, Hassibi, Babak
We consider the problem of coding over a half-duplex wireless relay network where both the transmitter and the receiver have respectively several transmit and receive antennas, whereas each relay is...
Efficient and Robust Compressed Sensing using High-Quality Expander Graphs (2008)
Jafarpour, Sina, Xu, Weiyu, Hassibi, Babak, Calderbank, Robert
Expander graphs have been recently proposed to construct efficient compressed sensing algorithms. In particular, it has been shown that any $n$-dimensional vector that is $k$-sparse (with $k\ll n$)...
The MIMO wiretap channel (2008)
Oggier, Frédérique, Hassibi, Babak
We study the MIMO wiretap channel, a MIMO broadcast channel where the transmitter sends some confidential information to one user which is a legitimate receiver, while the other user is an...
Modeling and Estimation for Real-Time Microarrays (2008)
Vikalo, Haris, Hassibi, Babak, Hassibi, Arjang
Microarrays are used for collecting information about a large number of different genomic particles simultaneously. Conventional fluorescent-based microarrays acquire data after the hybridization...
Recovering Sparse Signals Using Sparse Measurement Matrices in Compressed DNA Microarrays (2008)
Parvaresh, Farzad, Vikalo, Haris, Misra, Sidhant, Hassibi, Babak
Microarrays (DNA, protein, etc.) are massively parallel affinity-based biosensors capable of detecting and quantifying a large number of different genomic particles simultaneously. Among them, DNA...
Wireless Erasure Networks with Feedback (2008)
Consider a lossy packet network of queues, communicating over a wireless medium. This paper presents a throughput-optimal transmission strategy for a unicast network when feedback is available, which...
Data Transmission over Networks for Estimation and Control (2008)
Vijay Gupta, Student Member, Amir F. Dana, Student Member, João P. Hespanha, Richard M. Murray, ...
We consider the problem of controlling a linear time invariant process when the controller is located at a location remote from where the sensor measurements are being generated. The communication...
High Rate Codes with Bounded PMEPR for BPSK and Other Symmetric Constellations (2008)
In this letter, we consider the problem of constructing high rate codes with low peak to mean envelope power ratio (PMEPR) for multicarrier signals. Assuming coefficients of the multicarrier signal...
On the reconstruction of block-sparse signals with an optimal number of measurements (2008)
Stojnic, Mihailo, Parvaresh, Farzad, Hassibi, Babak
Let A be an M by N matrix (M < N) which is an instance of a real random Gaussian ensemble. In compressed sensing we are interested in finding the sparsest solution to the system of equations A x = y...
Speeding up the Sphere Decoder With ℋ∞ and SDP Inspired Lower Bounds (2008)
Stojnic, Mihailo, Vikalo, Haris, Hassibi, Babak
It is well known that maximum-likelihood (ML) decoding in many digital communication schemes reduces to solving an integer least-squares problem, which is NP hard in the worst-case. On the other...
Code Design for Multihop Wireless Relay Networks (2008)
Frédérique Oggier, Babak Hassibi
We consider a wireless relay network, where a transmitter node communicates with a receiver node with the help of relay nodes. Most coding strategies considered so far assume that the relay nodes are...
The idea of space-time coding devised for multiple-antenna systems is applied to the problem of communication over a wireless relay network, a strategy called distributed space-time coding, to...
Code Design for Multihop Wireless Relay Networks (2008)
Oggier, Frédérique, Hassibi, Babak
We consider a wireless relay network, where a transmitter node communicates with a receiver node with the help of relay nodes. Most coding strategies considered so far assume that the relay nodes are...
The idea of space-time coding devised for multiple-antenna systems is applied to the problem of communication over a wireless relay network, a strategy called distributed space-time coding, to...
Benjamin Recht, Weiyu Xu, Babak Hassibi
Minimizing the rank of a matrix subject to constraints is a challenging problem that arises in many applications in control theory, machine learning, and discrete geometry. This class of optimization...
Code Design for Multihop Wireless Relay Networks (2008)
Frédérique Oggier, Babak Hassibi
We consider a wireless relay network, where a transmitter node communicates with a receiver node with the help of relay nodes. Most coding strategies considered so far assume that the relay nodes are...
The idea of space-time coding devised for multiple-antenna systems is applied to the problem of communication over a wireless relay network, a strategy called distributed space-time coding, to...
Muñoz Fernández, Michela, Vilnrotter, Victor A., Mukai, Ryan, Hassibi, Babak
The performance of a coherent free-space optical communication system operating in the presence of turbulence is investigated. Maximum Likelihood Detection techniques are employed to optimally detect...
Tracking with an H∞ Criterion (2007)
In this paper we study the problem of tracking a reference signal from the H∞ point of view. As opposed to general H∞ problems, where only suboptimal solutions are obtained, we...
On Nonlinear Filters for Mixed H²/H∞ Estimation (2007)
We study the problem of mixed least-meansquares /H 1 -optimal (or mixed H 2 =H 1 -optimal) estimation of signals generated by discrete-time, finitedimensional, linear state-space models. The major...
On a Closed Form Solution to the Constant Modulus Factorization Problem (2007)
Babak Hassibi, Arogyaswami Paulraj, Thomas Kailath
We consider the problem of separating independent constant modulus signals received by an antenna array. Assuming that the statistics of the phases of the signals are known, we derive a closed form...
H∞ Adaptive Filtering (2007)
H 1 optimal estimators guarantee the smallest possible estimation error energy over all possible disturbances of fixed energy, and are therefore robust with respect to model uncertainties and lack of...
Least-Mean-Squares/H∞-Optimal Adaptive Filtering (2007)
In this paper we construct a so-called mixed least-meansquares /H 1 -optimal (or mixed H 2 =H 1 -optimal) algorithm for adaptive filtering. The resulting adaptive algorithm is nonlinear and requires...
H∞ Optimal Training Algorithms and their Relation to Backpropagation (2007)
We derive global H 1 optimal training algorithms for neural networks. These algorithms guarantee the smallest possible prediction error energy over all possible disturbances of fixed energy, and are...
Decision feedback equalization from an H� perspective (2007)
Alper T. Erdogan, Babak Hassibi, Thomas Kailath, Alper Tunga Erdogan
We approach the Multiple Input Multiple Output (MIMO) decision feedback equaliza-tion problem in digital communications from an H ∞ estimation point of view. Using the standard (and simplifying)...
Babak Hassibi, Mohammad Khorrami
A group of unitary matrices is called fixed-point-free (fpf) if all non-identity elements of the group have no eigenvalues at unity. Such groups are useful in multiple-antenna communications,...
The Secrecy Capacity of the MIMO Wiretap Channel (2007)
Oggier, Frédérique, Hassibi, Babak
We consider the MIMO wiretap channel, that is a MIMO broadcast channel where the transmitter sends some confidential information to one user which is a legitimate receiver, while the other user is an...
Normalized Entropy Vectors, Network Information Theory and Convex Optimization (2007)
Hassibi, Babak, Shadbakht, Sormeh
We introduce the notion of normalized entropic vectors -- slightly different from the standard definition in the literature in that we normalize entropy by the logarithm of the alphabet size. We...
Diversity-Multiplexing Gain Trade-off of a MIMO System with Relays (2007)
Rao, Chaitanya, Hassibi, Babak
We find the diversity-multiplexing gain trade-off of a multiple-antenna (MIMO) system with M transmit antennas, N receive antennas, R relay nodes, and with independent Rayleigh fading, in which the...
The problem of exact maximum-likelihood (ML) decoding of general linear codes is well-known to be NP-hard. In this paper, we show that exact ML decoding of a class of asymptotically good low density...
Efficient Compressive Sensing with Deterministic Guarantees Using Expander Graphs (2007)
Compressive sensing is an emerging technology which can recover a sparse signal vector of dimension n via a much smaller number of measurements than n. However, the existing compressive sensing...
Fundamental Limits in MIMO Broadcast Channels (2007)
Hassibi, Babak, Sharif, Masoud
This paper studies the fundamental limits of MIMO broadcast channels from a high level, determining the sum-rate capacity of the system as a function of system paramaters, such as the number of...
Delay Considerations for Opportunistic Scheduling in Broadcast Fading Channels (2007)
Sharif, Masoud, Hassibi, Babak
We consider a single-antenna broadcast block fading channel with n users where the transmission is packetbased. We define the (packet) delay as the minimum number of channel uses that guarantees all...
A coding scheme for wireless networks with multiple antenna nodes and no channel information (2007)
Oggier, Frédérique, Hassibi, Babak
In this paper, we present a coding strategy for wireless relay networks where the relay nodes are small devices with few resources, while the source and sink are equipped with multiple antennas to...
Statistical Pruning for Near-Maximum Likelihood Decoding (2007)
Gowaikar, Radhika, Hassibi, Babak
In many communications problems, maximum-likelihood (ML) decoding reduces to finding the closest (skewed) lattice point in N-dimensions to a given point xisin CN. In its full generality, this problem...
Algebraic Cayley Differential Space–Time Codes (2007)
Oggier, Frédérique, Hassibi, Babak
Cayley space-time codes have been proposed as a solution for coding over noncoherent differential multiple-input multiple-output (MIMO) channels. Based on the Cayley transform that maps the space of...
A Practical Scheme for Wireless Network Operation (2007)
Gowaikar, Radhika, Dana, Amir F., Hassibi, Babak, Effros, Michelle
In many problems in wireline networks, it is known that achieving capacity on each link or subnetwork is optimal for the entire network operation. In this paper, we present examples of wireless...
Since the classical work of Berlekamp, McEliece and van Tilborg, it is well known that the problem of exact maximum-likelihood (ML) decoding of general linear codes is NP-hard. In this paper, we show...
Sharif, Masoud, Hassibi, Babak
In this letter, we derive the scaling laws of the sum rate for fading multiple-input multiple-output Gaussian broadcast channels using time sharing to the strongest user, dirty-paper coding (DPC),...
Yeh, Hen-Geul, Chang, Yuan-Kwei, Hassibi, Babak
To mitigate intercarrier interference (ICI), a two-path algorithm is developed for multicarrier communication systems, including orthogonal frequency division multiplexing (OFDM) systems. The first...
In this paper, we derive the scaling laws of the sum rate for fading MIMO Gaussian broadcast channels using time-sharing to the strongest user, dirty paper coding (DPC), and beamforming when the...
On the Capacity Region of Multi-Antenna Gaussian Broadcast Channels with Estimation Error (2006)
Dana, Amir F., Sharif, Masoud, Hassibi, Babak
In this paper we consider the effect of channel estimation error on the capacity region of MIMO Gaussian broadcast channels. It is assumed that the receivers and the transmitter have (the same)...
How Much Does Transmit Correlation Affect the Sum-Rate of MIMO Downlink Channels? (2006)
Al-Naffouri, Tareq Y., Sharif, Masoud, Hassibi, Babak
This paper considers the effect of spatial correlation between transmit antennas on the sum-rate capacity of the MIMO broadcast channel (i.e., downlink of a cellular system). Specifically, for a...
Distributed Space-Time Coding in Wireless Relay Networks (2006)
We apply the idea of space-time coding devised for multiple-antenna systems to the problem of communications over a wireless relay network with Rayleigh fading channels. We use a two-stage protocol,...
The Effect of Channel Estimation Error on the Throughput of Broadcast Channels (2006)
Vakili, Ali, Sharif, Masoud, Hassibi, Babak
In a broadcast channel in which one transmitter serves n receivers, the capacity region highly depends on the amount of channel state information (CSI) at the transmitter. Assuming that the...
On joint detection and decoding of linear block codes on Gaussian vector channels (2006)
Optimal receivers recovering signals transmitted across noisy communication channels employ a maximum-likelihood (ML) criterion to minimize the probability of error. The problem of finding the most...
Rate maximization in multi-antenna broadcast channels with linear preprocessing (2006)
Stojnic, Mihailo, Vikalo, Haris, Hassibi, Babak
The sum rate capacity of the multi-antenna broadcast channel has recently been computed. However, the search for efficient practical schemes that achieve it is still ongoing. In this paper, we focus...
On the effect of quantization on performance at high rates (2006)
Gupta, Vijay, Dana, Amir F., Murray, Richard M., Hassibi, Babak
We study the effect of quantization on the performance of a scalar dynamical system in the high rate regime. We evaluate the LQ cost for two commonly used quantizers: uniform and logarithmic and...
Communication Over a Wireless Network With Random Connections (2006)
Gowaikar, Radhika, Hochwald, Bertrand, Hassibi, Babak
A network of nodes in which pairs communicate over a shared wireless medium is analyzed. We consider the maximum total aggregate traffic flow possible as given by the number of users multiplied by...
On the Power Efficiency of Sensory and Ad Hoc Wireless Networks (2006)
We consider the power efficiency of a communications channel, i.e., the maximum bit rate that can be achieved per unit power (energy rate). For additive white Gaussian noise (AWGN) channels, it is...
High-rate codes with bounded PMEPR for BPSK and other symmetric constellations (2006)
Sharif, Masoud, Hassibi, Babak
In this letter, we consider the problem of constructing high-rate codes with low peak-to-mean-envelope power ratio (PMEPR) for multicarrier signals. Assuming coefficients of the multicarrier signal...
Efficient joint maximum-likelihood channel estimation and signal detection (2006)
Vikalo, Haris, Hassibi, Babak, Stoica, Petre
In wireless communication systems, channel state information is often assumed to be available at the receiver. Traditionally, a training sequence is used to obtain the estimate of the channel....
A statistical model for microarrays, optimal estimation algorithms, and limits of performance (2006)
Vikalo, Haris, Hassibi, Babak, Hassibi, Arjang
DNA microarray technology relies on the hybridization process, which is stochastic in nature. Currently, probabilistic cross hybridization of nonspecific targets, as well as the shot noise (Poisson...
The p-norm generalization of the LMS algorithm for adaptive filtering (2006)
Kivinen, Jyrki, Warmuth, Manfred K., Hassibi, Babak
Recently much work has been done analyzing online machine learning algorithms in a worst case setting, where no probabilistic assumptions are made about the data. This is analogous to the H/sup /spl...
The p-norm generalization of the LMS algorithm for adaptive filtering (2006)
Kivinen, Jyrki, Warmuth, Manfred K., Hassibi, Babak
©2006 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale...
Capacity of wireless erasure networks (2006)
Dana, Amir F., Gowaikar, Radhika, Palanki, Ravi, Hassibi, Babak, Effros, Michelle
In this paper, a special class of wireless networks, called wireless erasure networks, is considered. In these networks, each node is connected to a set of nodes by possibly correlated erasure...
MIMO linear equalization with an H∞ criterion (2006)
Hassibi, Babak, Erdogan, Alper T., Kailath, Thomas
In this paper, we study the problem of linearly equalizing the multiple-input multiple-output (MIMO) communications channels from an H∞ point of view. H∞ estimation theory has been recently...
The p-Norm Generalization of the LMS Algorithm for Adaptive Filtering (2006)
Jyrki Kivinen, Manfred K. Warmuth, Babak Hassibi
Recently much work has been done analyzing online machine learning algorithms in a worst case setting, where no probabilistic assumptions are made about the data. This is analogous to the r setting...
Distributed space-time coding in wireless relay networks (2006)
We apply the idea of space-time coding devised for multiple-antenna systems to the prob-lem of communications over a wireless relay network with Rayleigh fading channels. We use a two-stage protocol,...
On the power efficiency of sensory and ad-hoc wireless networks (2006)
We consider the power efficiency of a communications channel, i.e., the maximum bit rate that can be achieved per unit power (energy rate). For AWGN channels, it is well known that power efficiency...
Differentiated rate scheduling for Gaussian broadcast channels (2005)
Sharif, Masoud, Dana, Amir F., Hassibi, Babak
In this paper, we consider a fading broadcast channel where users have different rate demands. In particular, we assume users are divided into M groups, each group of which requires the same rate,...
Three-transmit-antenna space-time codes based on SU(3) (2005)
Fully diverse constellations, i.e., a set of unitary matrices whose pairwise differences are nonsingular, are useful in multiantenna communications especially in multiantenna differential modulation,...
On the sphere-decoding algorithm I. Expected complexity (2005)
The problem of finding the least-squares solution to a system of linear equations where the unknown vector is comprised of integers, but the matrix coefficient and given vector are comprised of real...
In Part 1, we found a closed-form expression for the expected complexity of the sphere-decoding algorithm, both for the infinite and finite lattice. We continue the discussion in this paper by...
Amplitude and Sign Adjustment for Peak-to-Average-Power Reduction (2005)
Sharif, Masoud, Florens, Cedric, Fazel, Maryam, Hassibi, Babak
In this letter, we propose a method to reduce the peak-to-mean-envelope-power ratio (PMEPR) of multicarrier signals by modifying the constellation. For$M$-ary phase-shift keying constellations, we...
The p-norm generalization of the LMS algorithm for adaptive filtering (2005)
Kivinen, Jyrki, Warmuth, Manfred, Hassibi, Babak
Recently much work has been done analyzing online machine learning algorithms in a worst case setting, where no probabilistic assumptions are made about the data. This is analogous to the H-infinity...
Towards reducing the gap between PMEPR of multicarrier and single carrier signals (2005)
Sharif, Masoud, Hassibi, Babak
It has recently been shown that by altering the sign of each subcarrier in a multicarrier system significant reduction in the peak to mean envelope power (PMEPR) can be obtained. In fact, the PMEPR...
A delay analysis for opportunistic transmission in fading broadcast channels (2005)
Sharif, Masoud, Hassibi, Babak
We consider a single-antenna broadcast block fading channel (downlink scheduling) with n users where the transmission is packet-based and all users are backlogged. We define the delay as the minimum...
On the capacity of MIMO broadcast channels with partial side information (2005)
Sharif, Masoud, Hassibi, Babak
In multiple-antenna broadcast channels, unlike point-to-point multiple-antenna channels, the multiuser capacity depends heavily on whether the transmitter knows the channel coefficients to each user....
The p-norm generalization of the LMS algorithm for adaptive filtering (2005)
Jyrki Kivinen, Manfred K. Warmuth, Babak Hassibi
Abstract: Recently much work has been done analyzing online machine learning algorithms in a worst case setting, where no probabilistic assumptions are made about the data. This is analogous to the H...
Optimal LQG control across packet-dropping links (2005)
Vijay Gupta, Demetri Spanos, Babak Hassibi, Richard M Murray
We examine optimal Linear Quadratic Gaussian control for a system in which communication between the sensor (output of the plant) and the controller occurs across a packet-dropping link. We extend...
Design of fully diverse multiple-antenna codes based on Sp(2) (2004)
Fully diverse constellations, i.e., sets of unitary matrices whose pairwise differences are nonsingular, are useful in multiple-antenna communications, especially in multiple-antenna differential...
Gupta, Vijay, Chung, Timothy H., Hassibi, Babak, Murray, Richard M.
In this note we consider the following problem. Suppose a set of sensors is jointly trying to estimate a process. One sensor takes a measurement at every time step and the measurements are then...
Existence of codes with constant PMEPR and related design (2004)
Sharif, Masoud, Hassibi, Babak
Recently, several coding methods have been proposed to reduce the high peak-to-mean envelope ratio (PMEPR) of multicarrier signals. It has also been shown that with probability one, the PMEPR of any...
Analysis of multiple-antenna wireless links at low SNR (2004)
Rao, Chaitanya, Hassibi, Babak
Wireless channels with multiple transmit/receive antennas are known to provide a high spectral efficiency both when the channel is known to the receiver, and when the channel is not known to the...
On the capacity of frequency-selective channels in training-based transmission schemes (2004)
Vikalo, Haris, Hassibi, Babak, Hochwald, Bertrand, Kailath, Thomas
Communication systems transmitting over frequency-selective channels generally employ an equalizer to recover the transmitted sequence corrupted by intersymbol interference (ISI). Most practical...
Optimal LQG Control Across a Packet-Dropping Link (2004)
Gupta, Vijay, Spanos, Demetri, Hassibi, Babak, Murray, Richard M.
We examine optimal Linear Quadratic Gaussian control for a system in which communication between the sensor (output of the plant) and the controller occurs across a packet-dropping link. We extend...
A Sub-optimal Algorithm to Synthesize Control Laws for a Network of Dynamic Agents (2004)
Gupta, Vijay, Hassibi, Babak, Murray, Richard M.
We study the synthesis problem of an LQR controller when the matrix describing the control law is constrained to lie in a particular vector space. Our motivation is the use of such control laws to...
Peak to average power reduction using amplitude and sign adjustment (2004)
Sharif, Masoud, Florens, Cedric, Fazel, Maryam, Hassibi, Babak
In this paper, we propose a method to reduce the peak to mean envelope power ratio (PMEPR) of multicarrier signals by modifying the constellation. For MPSK constellations, we minimize the maximum of...
Scaling laws of sum rate using time-sharing, DPC, and beamforming for MIMO broadcast channels (2004)
Sharif, Masoud, Hassibi, Babak
We derive the scaling laws of the sum rate throughput for MIMO Gaussian broadcast channels using time-sharing to the strongest user, dirty paper coding (DPC), and beamforming when the number of users...
Delay guarantee versus throughput in broadcast fading channels (2004)
Sharif, Masoud, Hassibi, Babak
We consider a single-antenna broadcast fading channel with n backlogged users. Assuming the transmission is packet-based, we define the delay as the minimum number of channel uses that guarantees all...
Is broadcast plus multiaccess optimal for Gaussian wireless networks? (2004)
Dana, Amir F., Sharif, Masoud, Gowaikar, Radhika, Hassibi, Babak, Effros, Michelle
In this paper we show that "separation"-based approaches in wireless networks do not necessarily give good performance in terms of the capacity of the network. Therefore in optimal design of a...
On multicarrier signals where the PMEPR of a random codeword is asymptotically log n (2004)
Sharif, Masoud, Hassibi, Babak
Multicarrier signals exhibit a large peak-to-mean envelope power ratio (PMEPR). In this correspondence, without using a Gaussian assumption, we derive lower and upper probability bounds for the PMEPR...
MIMO decision feedback equalization from an H∞ perspective (2004)
Erdogan, Alper Tunga, Hassibi, Babak, Kailath, Thomas
We approach the multiple input multiple output (MIMO) decision feedback equalization (DFE) problem in digital communications from an H∞ estimation point of view. Using the standard (and...
On the achievable average power reduction of MSM optical signals (2004)
Sharif, Masoud, Hassibi, Babak
In this letter, we consider the achievable average power reduction of multiple subcarrier modulated optical signals by using optimized reserved carriers. Based on Nehari's result we present a lower...
On the capacity of wireless erasure networks (2004)
Gowaikar, Radhika, Dana, Amir F., Palanki, Ravi, Hassibi, Babak, Effros, Michelle
We determine the capacity of a certain class of wireless erasure relay networks. We first find a suitable definition for the "cut-capacity" of erasure networks with broadcast at transmission and no...
Practical schemes for wireless networks operation (2004)
Radhika Gowaikar, Amir F. Dana, Babak Hassibi, Michelle Effros
In many problems in wireline networks, it is known that achieving capacity on each link or sub-network is optimal for the entire network operation. In this paper we show that achieving capacity on...
Scheduling for Distributed Sensor Networks with Single Sensor Measurement per Time Step (2004)
Timothy H. Chung, Vijay Gupta, Babak Hassibi, Joel Burdick, Richard M. Murray
Abstract- We examine the prohlem of distributed estimation when only one sensor can take a measurement per time step. We solve lor the optimal recursive estimation algorithm when the sensor switching...
Practical schemes for wireless networks operation,” submitted to (2004)
Radhika Gowaikar, Amir F. Dana, Student Member, Student Member, Babak Hassibi, Michelle Effros, ...
Abstract—In many problems in wireline networks, it is known that achieving capacity on each link or subnetwork is optimal for the entire network operation. In this paper, we present examples of...
Scheduling for Distributed Sensor Networks with Single Sensor Measurement per Time Step (2004)
Timothy H. Chung, Vijay Gupta, Babak Hassibi, Joel Burdick, Richard M. Murray
Abstract — We examine the problem of distributed estimation when only one sensor can take a measurement per time step. We solve for the optimal recursive estimation algorithm when the sensor...
Optimal quantum detectors for unambiguous detection of mixed states (2003)
Eldar, Yonina C., Stojnic, Mihailo, Hassibi, Babak
We consider the problem of designing an optimal quantum detector that distinguishes unambiguously between a collection of mixed quantum states. Using arguments of duality in vector space...
Unitary space-time modulation via Cayley transform (2003)
A prevoiusly proposed method for communicating with multiple antennas over block fading channels is unitary space-time modulation (USTM). In this method, the signals transmitted from the antennas,...
On the capacity of MIMO broadcast channel with partial side information (2003)
Sharif, Masoud, Hassibi, Babak
Since having full channel state information in the transmitter is not reasonable in many applications and lack of channel knowledge does not lead to linear growth of the sum rate capacity as the...
The academic and industrial embrace of space-time methods (2003)
Hochwald, Bertrand M., Caire, Giuseppe, Hassibi, Babak, Marzetta, Thomas L.
[Guest Editors introduction to: Special issue on space-time transmission, reception, coding and signal processing] Every episode of the classic 1966–1969 television series Star Trek begins with...
On the existence of codes with constant bounded PMEPR for multicarrier signals (2003)
Sharif, Masoud, Hassibi, Babak
It has been shown that with probability one the peak to mean envelope power ratio (PMEPR) of any random codeword chosen from a symmetric QAM/PSK constellation is log n where n is the number of...
Sharif, Masoud, Hassibi, Babak
Multicarrier signals exhibit a large peak to mean envelope power ratio (PMEPR). In this paper, we derive the lower and upper probability bounds for the PMEPR distribution when entries of the...
Sharif, Masoud, Hassibi, Babak
Multiple subcarrier modulation (MSM) is an attractive technique for optical wireless communication for high speed applications. The main disadvantage of this scheme is its low average power...
How much training is needed in multiple-antenna wireless links? (2003)
Hassibi, Babak, Hochwald, Bertrand M.
Multiple-antenna wireless communication links promise very high data rates with low error probabilities, especially when the wireless channel response is known at the receiver. In practice, knowledge...
A deterministic algorithm that achieves the PMEPR of c log n for multicarrier signals (2003)
Sharif, Masoud, Hassibi, Babak
Multicarrier signals often exhibit large peak to mean envelope power ratios (PMEPR) which can be problematic in practice. In this paper, we study adjusting the sign of each subcarrier in order to...
Linear Network Codes: A Unified Framework for Source, Channel, and Network Coding (2003)
Michelle Effros, Muriel Medard, Tracey Ho, Siddharth Ray, David Karger, Ralf Koetter, ...
We examine the issue of separation and code design for network data transmission environments. We demonstrate that source-channel separation holds for several canonical network channel models when...
How much training is needed in multiple-antenna wireless links (2003)
Babak Hassibi, Bertrand M. Hochwald
Multiple-antenna wireless communication links promise very high data rates with low error probabilities, especially when the wireless channel response is known at the receiver. In practice, knowledge...
Sharif, Masoud, Hassibi, Babak
Multicarrier signals exhibit a large peak to mean envelope power ratio (PMEPR). In this paper; we derive lower and upper probability bounds for the PMEPR distribution when entries of the codeword, C,...
High-rate codes that are linear in space and time (2002)
Hassibi, Babak, Hochwald, Bertrand M.
Multiple-antenna systems that operate at high rates require simple yet effective space-time transmission schemes to handle the large traffic volume in real time. At rates of tens of bits per second...
Cayley differential unitary space-time codes (2002)
Hassibi, Babak, Hochwald, Bertrand M.
One method for communicating with multiple antennas is to encode the transmitted data differentially using unitary matrices at the transmitter, and to decode differentially without knowing the...
Hassibi, Babak, Marzetta, Thomas L.
An important open problem in multiple-antenna communications theory is to compute the capacity of a wireless link subject to flat Rayleigh block-fading, with no channel-state information (CSI)...
Hassibi, Babak, Marzetta, Thomas L.
An important open problem in multiple-antenna communications theory is to compute the capacity of a wireless link subject to flat Rayleigh block-fading, with no channel-state information (CSI)...
Structured unitary space-time autocoding constellations (2002)
Marzetta, Thomas L., Hassibi, Babak, Hochwald, Bertrand M.
We previously showed that arbitrarily reliable communication is possible within a single coherence interval in Rayleigh flat fading as the symbol duration of the coherence interval and the number of...
Multiple antenna systems are capable of providing high data rate transmissions over wireless channels. When the channels are dispersive, the signal at each receive antenna is a combination of both...
Multiple antenna systems are capable of providing high data rate transmissions over wireless channels. When the channels are dispersive, the signal at each receive antenna is a combination of both...
Cayley differential unitary space-time codes (2002)
Babak Hassibi, Bertrand M. Hochwald
One method for communicating with multiple antennas is to encode the transmitted data differentially using unitary matrices at the transmitter, and to decode differentially without knowing the...
Structured unitary space-time autocoding constellations (2002)
Thomas L. Marzetta, Babak Hassibi, Bertrand M. Hochwald
We recently showed that arbitrarily reliable communication is possible within a single coherence interval in Rayleigh flat fading as the symbol-duration of the coherence interval and the number of...
High-rate codes that are linear in space and time (2002)
Babak Hassibi, Bertrand M. Hochwald
Multiple-antenna systems that operate at high rates require simple yet effective space-time transmission schemes to handle the large traffic volume in real time. At rates of tens of bits/sec/Hz,...
Multiple antenna systems are capable of providing high data rate transmissions over wireless channels. When the channels are dispersive, the signal at each receive antenna is a combination of both...
Multiple antenna systems are capable of providing high data rate transmissions over wireless channels. When the channels are dispersive, the signal at each receive antenna is a combination of both...
Hochwald, Bertrand M., Marzetta, Thomas L., Hassibi, Babak
Prior treatments of space-time communications in Rayleigh flat fading generally assume that channel coding covers either one fading interval-in which case there is a nonzero “outage capacity”-or...
Representation theory for high-rate multiple-antenna code design (2001)
Shokrollahi, Amin, Hassibi, Babak, Hochwald, Bertrand M., Sweldens, Wim
Multiple antennas can greatly increase the data rate and reliability of a wireless communication link in a fading environment, but the practical success of using multiple antennas depends crucially...
H∞ bounds for least-squares estimators (2001)
Hassibi, Babak, Kaliath, Thomas
We obtain upper and lower bounds for the H∞ norm of the Kalman filter and the recursive-least-squares (RLS) algorithm, with respect to prediction and filtered errors. These bounds can be used to...
Estimation-based synthesis of H∞-optimal adaptive FIR filtersfor filtered-LMS problems (2001)
Sayyarrodsari, Bijan, How, Jonathan P., Hassibi, Babak, Carrier, Alain
This paper presents a systematic synthesis procedure for H∞-optimal adaptive FIR filters in the context of an active noise cancellation (ANC) problem. An estimation interpretation of the adaptive...
Babak Hassibi, Thomas L. Marzetta
An important open problem in multiple antenna communications theory is to compute the capacity of a wireless link subject to flat Rayleigh block-fading, with no channel-state information available...
Estimation-Based Synthesis of H∞-Optimal Adaptive FIR Filters for Filtered-LMS Problems (2001)
Bijan Sayyarrodsari, Jonathan P. How, Babak Hassibi, Alain Carrier
This paper presents a systematic synthesis procedure for-optimal adaptive FIR filters in the context of an active noise cancellation (ANC) problem. An estimation interpretation of the adaptive...
Babak Hassibi, Thomas L. Marzetta
An important open problem in multiple antenna communications theory is to compute the capacity of a wireless link subject to flat Rayleigh block-fading, with no channel-state information available...
On linear H∞ equalization of communication channels (2000)
Erdogan, Alper T., Hassibi, Babak, Kailath, Thomas
As an alternative to existing techniques and algorithms, we investigate the merit of the H∞ approach to the linear equalization of communication channels. We first give the formulation of all...
Array algorithms for H-infinity estimation (2000)
Hassibi, Babak, Kailath, Thomas, Sayed, Ali H.
In this paper we develop array algorithms for H-infinity filtering. These algorithms can be regarded as the Krein space generalizations of H-2 array algorithms, which are currently the preferred...
Representation Theory for High-Rate Multiple-Antenna Code Design (2000)
Babak Hassibi, Bertrand M. Hochwald, Amin Shokrollahi, Wim Sweldens
this paper, we show how to design signal matrices satisfying these requirements. As shown in [1], the design problem for unitary space time constellations is the following: let
An Efficient Square-Root Algorithm for BLAST (2000)
Bell Labs Layered Space-Time (BLAST) is a scheme for transmitting information over a rich-scattering wireless environment using multiple receive and transmit antennas. The main computational...
How Much Training is Needed in Multiple-Antenna Wireless Links? (2000)
Babak Hassibi, Bertrand Hochwald
....
Structured Unitary Space-Time Autocoding Constellations (2000)
Thomas L. Marzetta, Babak Hassibi, Bertrand M. Hochwald
We recently showed that arbitrarily reliable communication is possible within a single coherence interval in Rayleigh flat fading as the symbol-duration of the coherence interval and the number of...
High-Rate Codes that are Linear in Space and Time (2000)
Babak Hassibi, Bertrand Hochwald
Multiple-antenna systems that operate at high rates require simple yet effective space-time transmission schemes to handle the large traffic volume in real time. At rates of tens of bits/sec/Hz,...
On Linear H∞ Equalization of Communication Channels (2000)
Alper T. Erdogan, Babak Hassibi, Thomas Kailath
As an alternative to existing techniques and algorithms, we investigate the merit of the H # approach to the linear equalization of communication channels. We first give the formulation of all causal...
Fully-diverse multiple-antenna signal constellations and fixed-point-free Lie groups (2000)
Babak Hassibi, Mohammad Khorrami
A group of unitary matrices is called xed-point-free (fpf) if all non-identity elements of the group have no eigenvalues at unity. Such groups are useful in multiple-antenna communications,...
Bertrand M. Hochwald, Thomas L. Marzetta, Babak Hassibi
Prior treatments of space-time communications in Rayleigh flat fading generally assume that channel coding covers either one fading interval---in which case there is a nonzero "outage...
Haitham A. Hindi, Babak Hassibi, Stephen P. Boyd
The problem of multiobjective H2=H1 optimal controller design is reviewed. There is as yet no exact solution to this problem. We present a method based on that proposed by Scherer [14]. The problem...
H∞ Bounds for Least-Squares Estimators (1997)
In this paper we obtain upper and lower bounds for the H 1 norm of the Kalman filter and RLS algorithm, with respect to prediction and filtered errors. These bounds can be used to study the...
Array Algorithms for H² and H∞ Estimation (1997)
Babak Hassibi, Thomas Kailath, Ali H. Sayed
Currently, the preferred method for implementing H² estimation algorithms is what is called the array form, and includes two main families: square-root array algorithms which are typically...
On Optimal Solutions to Two-Block H∞ Problems (1997)
In this paper we obtain a new formula for the minimum achievable disturbance attenuation in two-block H 1 problems. This new formula has the same structure as the optimal H 1 norm formula for...
Equalization with an H∞ Criterion (1997)
Babak Hassibi, Alper T. Erdogan, Thomas Kailath
In this paper we study the problem of equalizing a communications channel from an H 1 point of view. H 1 estimation theory has been recently introduced as a method for designing filters that have...
A Krein Space Interpretation of the Kalman-Yakubovich-Popov Lemma (1997)
In this note we give a Krein space interpretation of the celebrated Kalman-Yakubovich-Popov (KYP) Lemma by introducing state-space models driven by inputs that lie in an indefinite-metric space. Such...
Inertia properties of indefinite quadratic forms (1996)
Sayed, Ali H., Hassibi, Babak, Kailath, Thomas
We study the relation between the solutions of two estimation problems with indefinite quadratic forms. We show that a complete link between both solutions can be established by invoking a...
H∞ optimality of the LMS algorithm (1996)
Hassibi, Babak, Sayed, Ali H., Kailath, Thomas
We show that the celebrated least-mean squares (LMS) adaptive algorithm is H∞ optimal. The LMS algorithm has been long regarded as an approximate solution to either a stochastic or a deterministic...
Linear estimation in Krein spaces. I. Theory (1996)
Hassibi, Babak, Sayed, Ali H., Kailath, Thomas
The authors develop a self-contained theory for linear estimation in Krein spaces. The derivation is based on simple concepts such as projections and matrix factorizations and leads to an interesting...
Linear estimation in Krein spaces. II. Applications (1996)
Hassibi, Babak, Sayed, Ali H., Kailath, Thomas
We have shown that several interesting problems in H∞-filtering, quadratic game theory, and risk sensitive control and estimation follow as special cases of the Krein-space linear estimation theory...
Indefinite metric spaces in estimation, control and adaptive filtering / (1996)
Submitted to the Department of Electrical Engineering.
Linear Estimation in Krein Spaces - Part I: Theory (1996)
Babak Hassibi, Ali H. Sayed, Thomas Kailath
We develop a self-contained theory for linear estimation in Krein spaces. The derivation is based on simple concepts such as projections and matrix factorizations, and leads to an interesting...
Linear Estimation in Krein Spaces - Part II: Applications (1996)
Babak Hassibi, Ali H. Sayed, Thomas Kailath
We show that several interesting problems in H 1 \Gammafiltering, quadratic game theory and risk sensitive control and estimation, follow as special cases of the Krein space linear estimation theory...
H∞ Optimality of the LMS Algorithm (1995)
Babak Hassibi, Ali H. Sayed, Thomas Kailath
We show that the celebrated LMS (Least-Mean Squares) adaptive algorithm is H 1 optimal. The LMS algorithm has been long regarded as an approximate solution to either a stochastic or a deterministic...
H∞ Optimality Criteria for LMS and Backpropagation (1994)
Babak Hassibi, Ali H. Sayed, Thomas Kailath
We have recently shown that the widely known LMS algorithm is an H 1 optimal estimator. The H 1 criterion has been introduced, initially in the control theory literature, as a means to ensure robust...
Second Order Derivatives for Network Pruning: Optimal Brain Surgeon (1993)
We investigate the use of information from all second order derivatives of the error function to perform network pruning (i.e., removing unimportant weights from a trained network) in order to...