No abstract

In this work, we study the performance of a single relay Multiple Input Multiple Output (MIMO) cooperative communication system based on Decode and Forward (DF) relaying protocol for two strategies using transmit antenna selection at the source. The first strategy uses one antenna between the relay and the destination, and the second strategy uses Space Time Block Coding (STBC). All channels follow the Rayleigh fading distribution. We derive the expression and Upper Bound for Symbol Error Rate (SER) for M-ary Phase Shift Keying (M-PSK), and the diversity order for both strategies. The analytical results show that the second strategy performs better than the first one for the same diversity order and the same Rate R.

In this Letter, the authors consider a multi-unicast flow wireless communication system with a retransmission scheme. The effective capacity (EC) is used as a performance metric in order to make use of the recurrence relation approach. They also take advantage of network coding (NC) as combined with automatic repeat request (ARQ) protocol (NC-ARQ), for more robust communication. The authors' main contribution, in this work, is the derivation of the EC for M-user NC-ARQ using only the opportunity of XoR-ing M packets. They then, focus on a 3-user system and derive the EC using the opportunity of XoR-ing packets for 3 and 2 users. An interesting result is the fact that, contrary to expectation, as the number of users in a network that uses NC-ARQ increases, the performance in terms of EC increases as well, depending on how the sender schedules and manages the retransmissions.