Impact Analysis of Reciprocity Mismatch in Relaying Systems Cooperative beamforming can provide a significant performance improvement for relaying system with the help of the channel state information (CSI). In timedivision duplexing (TDD) mode, the estimated CSI will deteriorate due to the reciprocity mismatch. In this work, we examine the impact of the reciprocity mismatch in relaying systems. To evaluate the impact of the reciprocity mismatch for all the devices including sources, relays, and destinations, the closedform expression of the achievable rate is derived. Then, we analyze the performance loss caused by the mismatch at the source side, the relay side, and the destination side respectively to show that the mismatch at the relay side dominates the impact. Simulation results are presented to verify the analytical results.

Bit error rate performance analysis of ACMAP in multiple input single output wireless relay network In this paper, we propose a joint decoding scheme called ACMAP decoder for multiple input single output (MISO) wireless cooperative communication network that consists of single source, single relay, and single destination. The proposed scheme is based on both Alamouti combining (AC) scheme and maximum a posteriori (MAP) decoder and is used to estimate the data at the destination. The ACMAP decoder is optimal in the sense that it minimizes the endtoend bit error rate (BER). In order to analyze performance of the proposed decoder, we derive a closed form expression for the upper bound (UB) on the endtoend error probability. Distances between system nodes, transmit energy, and channel noise and fading effects are considered in the derivation of the UB. Numerical results show that the closed form UB is very tight and it almost coincides with the exact BER results obtained from simulations. Therefore, we use the derived UB expression to study the effects of the relay position on the BER performance and to find the optimal location of the relay node.