Evaluating cooperative diversity-based WBAN by using STBC with pre-coding and relay selection

The main objective of this paper is to evaluate the network performance of a cooperative diversity-based wireless body area network (WBAN) by using (2,2) Alamouti´s space-time block code (STBC) with pre-coding scheme (STBC-PC) and a relay selection procedure (RSP). The considered WBAN model is served for healthcare service in order to mitigate the undesired effects of WBAN due to high path loss and fading as well as to keep a low transmit power while meeting to the desired WBAN quality of services. In this paper, the pre-coding scheme is taken to be employed in conjunction with the STBC, since a single antenna of each wireless sensor node in healthcare service can be exploited possibly as well as the high gain can still be achieved without loss of transmission rate. A channel model CM3 B is considered for computing the actual path loss of each WBAN link and the network performance is evaluated in terms of bit error rate (BER). The simulation results confirm that at each BER value, SNRs of STBC-PC without direct link (line-of-sight or LOS) scheme are the lowest which is compared with direct link, receive diversity and MRC, and (2,2) Alamouti´s STBC. BER values of DQPSK-based STBC-PC are higher than those of DBPSK-based STBC-PC. Moreover, although any WBAN sensor nodes are chosen as a relay or any type of modulations are employed in STBC-PC with LOS, all of BER values have surprisingly the same trend.