TAS Protocols of a PASD System with Limited Feedback Information

In a protocol assisted switched diversity (PASD) system, the time separated repetition blocks are accumulated in order to increase decoding reliability. In this paper, we consider transmit antenna selection (TAS) protocols in a PASD system. To minimize system complexity we assume the feedback information is limited to the SNR of the current pair of antennas. We propose three TAS protocols : the random TAS (R-TAS) protocol which selects antennas randomly, the threshold TAS (T-TAS) protocol which keeps the current selection if the predetermined SNR threshold level requirement is met and the minimum number of transmission TAS (MNT-TAS) protocol which determines the selection of a new antenna set or keeping the current set based on the evaluation of expectation of the number of necessary remaining transmissions. We analyze the average number of transmissions of three proposed protocols in a Rayleigh fading channel and compare numerical evaluations to simulation results under different system conditions.