Performance analysis of space-time coding with imperfect channel estimation

Abstract

Abstract-We analyze the error performance of a space-time coding system using transmit and receive antennas with imperfect channel estimation in flat Rayleigh fading. A least-squares estimate of the channel matrix is obtained by using a sequence of pilot code vectors. The estimate is found to be perturbed by an perturbation matrix with zero-mean circular Gaussian entries. Using the characteristic function of the decision variable, we derive a closed-form expression for the pairwise error probability (PEP). From the same expression, the PEP in case of perfect channel estimation is also obtained. Numerical results show the degradation in performance due to imperfect channel estimation that can be compensated by increasing the number of receive antennas.

A unified receiver for MIMO communication with imperfect channel knowledge

“…The performance of the MMLD is clearly worse than that of the ML detector and the performance gap depends on σ 2 w [2]. As σ 2 w approaches 0, Z approaches H and the performance of the MMLD approaches that of the optimal ML detector in (2).…”

“…As σ 2 w approaches 0, Z approaches H and the performance of the MMLD approaches that of the optimal ML detector in (2). When no estimate of the channel is available, equation (3) is no longer valid and the MMLD in (4) fails to provide any useful detection.…”

“…With inevitable channel estimation errors, this receiver is no longer optimal and it This work was supported in part by the National Science Foundation under grant CCF-0725366 and in part by Huawei Technologies Co. Ltd. exhibits significant performance degradation [2]- [4]. An ML receiver that makes use of an imperfect channel estimate is referred to as a Mismatched Maximum Likelihood Detector (MMLD) [3].…”

Performance of a MIMO receiver using joint channel-symbol estimation in the presence of channel errors

“…Under high mobility situations, this problem is especially acute because the channel needs to be estimated more frequently which places significant pilot overhead and reduces system throughput. Compromising the quality of the channel estimate through the minimal usage of pilots results in severe performance degradation of the conventional Mismatched Maximum Likelihood (MML) MIMO receiver [1], [2]. A better receiver structure then is one which relies of joint channel-symbol estimation techniques [3], [4], [5].…”

Optimum and Suboptimum Receivers for Space-Time Coded Systems in Correlated Fading

“…The M × N channel matrix is estimated prior to the data transmission from known pilot code vectors transmitted over a duration of L p symbol intervals. The CSI thus obtained is imperfect [4,5], and when in the decision variable processor at the receiver, the exact channel matrix is replaced by its imperfect estimate, it does not give an optimum decision criterion in the maximum likelihood (ML) sense. In this paper we consider three receiver structures given by [6]: (1) a suboptimum one in which in a perfect ML receiver the imperfect CSI is used in place of perfect CSI, (2) the optimum receiver I in which the imperfect CSI is used in the ML sense, (3) the optimum receiver II that jointly processes the received data code and the pilot code.…”