Distributed turbo codes with multiple-relays and multi-receive antennas at the destination for non-line of sight source-destination link with unknown CSI

This paper presents the half-duplex coded-cooperative scheme for non-line of sight communication systems. Multiple-relays are divided in two groups which are frequency division multiplexed and participate in coded-cooperation. Antenna array is used at the destination to obtain multi-receive diversity. Maximal ratio combining (MRC) is used at the destination to combine the signals transmitted at different relays. Rician fading channel is assumed among all the communication nodes. Moreover, channel state information (CSI) is assumed unknown at the destination. The unknown CSI is estimated using adaptive Spatio-temporal recursive least squares (ST-RLS) algorithm. Turbo codes are utilized to provide coded-cooperative diversity and joint iterative decoding scheme is utilized at the destination. The overall end-to-end bit error rate (BER) performance of the coded-cooperative scheme is analyzed with the help of Monte-Carlo simulations. The numerical simulations show that the proposed scheme provides coded-cooperative diversity, multi-receive diversity and clearly outperforms the non-cooperative transmission scheme under the identical conditions.