Iterative Transceiver Design Research Articles

MMSE-Based Transceiver Design Algorithms for Interference MIMO Relay Systems

In this paper, we investigate the transceiver design for amplify-and-forward interference multiple-input multiple-output (MIMO) relay communication systems, where multiple transmitter-receiver pairs communicate simultaneously with the aid of a relay node. The aim is to minimize the mean-squared error (MSE) of the signal waveform estimation at the receivers subjecting to transmission power constraints at the transmitters and the relay node. As the transceiver optimization problem is nonconvex with matrix variables, the globally optimal solution is intractable to obtain. To overcome the challenge, we propose an iterative transceiver design algorithm where the transmitter, relay, and receiver matrices are optimized iteratively by exploiting the optimal structure of the relay precoding matrix. To reduce the computational complexity of optimizing the relay precoding matrix, we propose a simplified relay matrix design through modifying the transmission power constraint at the relay node. The modified relay optimization problem has a closed-form solution. Simulation results demonstrate that the proposed algorithms perform better than the existing techniques in terms of both MSE and bit-error-rate.

Iterative Transceiver Design for Opportunistic Interference Alignment in MIMO Interfering Multiple-Access Channels

In this paper, we propose an iterative transceiver design algorithm for opportunistic interference alignment in MIMO interfering multiple-access channels. The proposed algorithm iteratively optimizes the transmit beamforming vectors, the receive matrices and the user selection set, which digs into the multiuser diversity gain. Specifically, data transmission can be operated in each iteration using the updated transceiver and the selected user set, which means that no additional processing delay is introduced. Simulation results demonstrate the improved average rate per cell performance of the proposed algorithm compared to the conventional ones. Index Terms—Interference alignment, OIA, user scheduling, iterative

Transceiver Design Using Local Channel State Information at Relays for A Multi-Relay Multi-User MIMO Network

In this paper, we propose an iterative transceiver design in a multi-relay multi-user multiple-input multiple-output (MIMO) system. The design criterion is to minimize sum mean squared error (SMSE) under relay sum power constraint (RSPC) where only local channel state information (CSI)s are available at relays. Local CSI at a relay is defined as the CSI of the channel between BS and the relay in the 1 st hop link, and the CSI of the channel between the relay and all users in the 2 nd hop link. Exploiting BS transmitter structure which is concatenated with block diagonalization (BD) precoder, each relay’s precoder can be determined using local CSI at the relay. The proposed scheme is based on sequential iteration of two stages; stage 1 determines BS transmitter and relay precoders jointly with SMSE duality, and stage 2 determines user receivers. We verify that the proposed scheme outperforms simple amplify-and-forward (SAF), minimum mean squared error (MMSE) relay, and an existing good scheme of [13] in terms of both SMSE and sum-rate performances.

Minimizing Sum-MSE Implies Identical Downlink and Dual Uplink Power Allocations

In the multiuser downlink, power allocation for linear precoders that minimize the sum of mean squared errors under a sum power constraint is a non-convex problem. Many existing algorithms solve an equivalent convex problem in the virtual uplink and apply a transformation based on uplink-downlink duality to find a downlink solution. In this letter, we analyze the optimality criteria for the power allocation subproblem in the virtual uplink, and demonstrate that the optimal solution leads to identical power allocations in the downlink and virtual uplink. We thus extend the known duality results and, importantly, simplify the existing algorithms used for iterative transceiver design.

Iterative Transceiver Design for MIMO ARQ Retransmissions With Decision Feedback Detection

This paper investigates the problem of progressive transceiver design for integrated multi-input multioutput (MIMO) systems with automatic repeat request (ARQ) capability. We consider a generic MIMO transceiver architecture that utilizes a linear transmission precoder and a linear decoder followed by decision feedback interference cancellation at the receiver. To be consistent with ARQ, our goal is to progressively design the optimal transmission precoder and receiver feedback system to jointly minimize the mean square error (MSE) under the assumption of perfect feedback. We consider both zero-forcing and minimum MSE (MMSE) decoder as joint ARQ receivers. Unlike in single transmission design, joint ARQ receivers cannot change previous precoders. Here, we propose an approach to design the precoder and receiver which improves the system performance successively over each retransmission to achieve MSE performance close to the known lower bound.