Joint Space-time Decoding Research Articles

Automatic Robust Linear Receiver for Multi-Access Space-Time Block Coded MIMO Systems

In this letter, we develop a fully automatic robust linear receiver technique for joint space-time decoding and interference rejection in multi-access MIMO systems that use orthogonal space-time block codes and erroneous channel state information (CSI). The proposed receiver does not need any a priori knowledge of channel estimation errors and has a simple closed form. Numerical examples show that our method usually gives good performance in case of non-perfect CSI and/or low sample sizes when compared with other tested linear receivers.

User cooperation in an asynchronous cellular uplink

We present in this paper, multiuser decode-and-forward (DF) sharing scheme and a practical low-complexity adaptive pseudo-linear receiver design for cooperative diversity in an asynchronous cellular uplink. The DF schemes provide near maximum-likelihood (ML) performance, including full diversity and significant throughput improvements over no-sharing and existing schemes, under linear receiver design. The proposed linear receiver jointly separates users while suppressing the multiple-access interference (i.e., employs multiuser detection) and performs space-time decoding for diversity exploitation. We provide bit-error-probability and throughput simulations for the practical, noisy inter-user channels. The simulation results demonstrate that the three-user sharing scheme fully exploits available diversity with inter-user demodulation errors as high as 0.1% using linear joint space-time decoding and multiuser detection.

Robust linear receivers for space-time block coded multiaccess MIMO systems with imperfect channel state information

Recently, several linear receiver algorithms have been developed for space-time block-coded multiaccess multiple-input multiple-output (MIMO) wireless communication systems. All these techniques are based on the assumption that the channel state information (CSI) at the receiver side is perfect. However, in practical situations, the available CSI may be imperfect because of channel estimation errors and/or outdated training. In this paper, we develop new robust linear receiver techniques for joint space-time decoding and interference rejection in multiaccess MIMO systems that use orthogonal space-time block codes and erroneous CSI. The proposed receivers are based on worst-case performance optimization. They are shown to provide a substantially improved robustness against CSI mismatches as compared with the existing linear multiaccess MIMO receivers.

Minimum Variance Linear Receivers for Multiaccess MIMO Wireless Systems with Space-Time Block Coding

We consider the problem of joint space-time decoding and multiaccess interference (MAI) rejection in multiuser multiple-input multiple-output (MIMO) wireless communication systems. We address the case when both the receiver and multiple transmitters are equipped with multiple antennas and when space-time block codes (STBCs) are used to send the data simultaneously from each transmitter to the receiver. A new linear receiver structure is developed to decode the data sent from the transmitter-of-interest while rejecting MAI, self-interference, and noise. The proposed receivers are designed by minimizing the output power subject to constraints that zero-force self-interference and/or preserve a unity gain for all symbols of the transmitter-of-interest. Simulation results show that in multiaccess scenarios, the proposed techniques have substantially lower symbol error rates as compared with the matched filter (MF) receiver, which is equivalent to the maximum likelihood (ML) space-time decoder in the point-to-point MIMO communication case.