Retransmission transceiver designs for wireless communications

Traditionally, error control coding, Automatic Repeat reQuest (ARQ, and signal processing techniques have been treated independently. To improve overall system efficiency, we study methods to take advantage of all three techniques simultaneously. We begin our study by investigating blind channel estimation and equalization of multiple packet transmissions using subspace methods. We propose to improve overall bandwidth efficiency by allowing for smarter packet retransmissions. Before retransmitting a packet, we reduce the number of symbols required for retransmission to save bandwidth, afterwards, we utilize the structure created by this partial retransmission to increase the efficiency of the subspace algorithm for channel estimation. We prove that the channel can be more easily identified when only part of the information is retransmitted. We extend this idea to the more modern communication architecture called Orthogonal Frequency Division Multiplexing (OFDM).; After looking at channel estimation in single carrier and multi-carrier systems, we look at partial packet retransmission in multiple antenna systems. We utilize the structure created by partial retransmissions once again in space-time block coded (STBC) systems. We take an orthogonal space-time code and transform it into an more power-bandwidth efficient embedded quasi-orthogonal space-time block code.; After we look at space-time block coded multiple antenna systems, we investigate our partial retransmission scheme over spatial multiplexed multiple input multiple output (MIMO) systems. In advanced MIMO systems, linear precoders and decoders are used due to their low complexity and relatively high performance. The main design challenge for MIMO systems is determining the optimal precoders and decoders. We develop an algorithm to find an efficient precoder and decoder for partial retransmission systems and we show that our partial retransmission MIMO system is more bandwidth-power efficient than traditional precoder designs.; Lastly, we turn our attention away from partial retransmission and look at coded modulation systems. In coded modulation schemes, coding and signal detection are combined jointly to form a more efficient system. When coded modulation is combined with retransmission, it is done from a coding perspective. We look at combining retransmission and coded modulation adopting a signal processing perspective. During retransmission, we change the bit to symbol mapping and exploit the mapping diversity at the receiver in order to achieve larger coding gains without increasing complexity.