Quasi-Orthogonal Design and Performance Analysis of Amplify-And-Forward Relay Networks with Multiple-Antennas

Abstract

Abstract-This paper is on the design and performance analysis of practical distributed space-time codes for wireless relay networks with multiple antennas terminals. The amplify-andforward scheme is used in a way that each relay transmits a scaled version of the linear combination of the received symbols. We propose distributed generalized quasi-orthogonal space-time codes which are distributed among the source antennas and relays, and valid for any number of relays. Assuming M -PSK and M -QAM signals, we derive a formula for the symbol error probability of the investigated scheme over Rayleigh fading channels. For sufficiently large SNR, this paper derives closed-form average SER expression. The simplicity of the asymptotic results provides valuable insights into the performance of cooperative networks and suggests means of optimizing them. Our analytical results have been confirmed by simulation results, using full-rate full-diversity distributed codes. I. INTRODUCTIONIn [1], a cooperative strategy was proposed which achieves a diversity factor of R in a R-relay wireless network, using the distributed space-time codes (DSTC). A two-phase protocol is used for this strategy. In phase one, the transmitter sends the information signal to the relays and in phase two, relays send information to the receiver. The signal sent by every relay in the second phase is designed as a linear function of its received signal. It was shown that the relays can generate a linear space-time codeword at the receiver, as in a multiple antenna system, although they only cooperate distributively. This method does not require decoding at the relays and for high SNR it achieves the optimal diversity factor [1]. Recently, the design of practical DSTC in amplify-and-forward (A&F) mode, that lead to reliable communication in wireless relay networks, has been presented in [2] and [3].Distributed space-time coding in A&F mode was generalized to networks with multiple-antenna nodes in [4]. However, design of the appropriate space-time codes is not investigated in [4]. Note that in decode-and-forward (D&F) based spacetime codes, we can simply use the same space-time codes in the context of MIMO in multiple antenna source and relays [5]. Compared with D&F, since no decoding is needed at the relays, A&F DSTC saves both time and energy and more importantly, there is no rate constraint on the transmission.In this paper, we focus on the design of the quasi-orthogonal DSTCs for multiple-antenna terminals with A&F relays, which

Distributed GABBA space-time codes in amplify-and-forward relay networks

“…Distributed space-time coding was generalized to networks with multipleantenna nodes in [53], and the design of practical DSTCs with multiple antennas terminals has also been recently considered in [48,54,55]. In [54,55], which due to the space limitation we have not included them in this thesis, the orthogonal and quasi-orthogonal space-time design is used for A&F based wireless relay networks with multiple-antenna nodes.…”

Adaptive Distributed Space-Time Coding Based on Adjustable Code Matrices for Cooperative MIMO Relaying Systems

“…denotes the received symbol vector without noise which is determined by substituting each column of S into (11). It is worth to mention that the optimization algorithm contains a discrete part which refers to the ML detection and a continuous part which refers to the optimization of the code matrix, and the detection and the optimization can be implemented separately as they do not depend on each other.…”

“…An adaptive distributed-Alamouti (DAlamouti) space-time block code (STBC) design is proposed in [8] for non-regenerative dual-hop wireless systems which achieves the minimum outage probability. DSTC schemes for the AF protocol are discussed in [9]- [11]. In [9], the GABBA STC scheme is extended to a distributed MIMO network with full-diversity and full-rate, while an optimal algorithm for the design of the DSTC scheme to achieve the optimal diversity and multiplexing tradeoff is derived in [10].…”

“…In [9], the GABBA STC scheme is extended to a distributed MIMO network with full-diversity and full-rate, while an optimal algorithm for the design of the DSTC scheme to achieve the optimal diversity and multiplexing tradeoff is derived in [10]. A quasi-orthogonal DSTBC for cooperative MIMO networks is presented and shown to achieve full rate and full diversity with any number of antennas in [11]. In [12], a new STC scheme that multiplies a randomized matrix by the STC matrix at the relay node before the transmission is derived and analyzed.…”

Delay-tolerant distributed space-time coding with feedback for cooperative MIMO relaying systems

“…In addition, the work on delay-tolerant DSTC has focused on encoding using a fixed scheme, such as TAST codes in [10], which are difficult to implement with other DSTC schemes. In the literature, the DSTC designs in [17][18][19][20][21][22][23] can achieve full diversity order and high coding gains but are vulnerable to delays. In order to improve the existing DSTC schemes and overcome the delay issues, a general delay-tolerant encoding design and algorithm is needed.…”