A Novel Cooperative Diversity Technique Based on Multilevel Pseudo Space-Time Trellis Coding

Several multilevel space-time trellis coding (MLSTTC) techniques have been investigated in the past few years to attain the benefits of spectral efficiency, coding gain and diversity gain. However, these techniques require multiple transmit antennas for their operation and cannot be used for mobile nodes with size, cost or hardware constraint. This study proposes a cooperative transmission technique for single-antenna mobile nodes using novel multilevel pseudo space-time trellis coding (MLPSTTC). Each mobile node behave as a cooperating node and decodes the information transmitted by other mobile nodes to the common destination node. The self-information of a cooperating node and decoded information of other nodes is further encoded using multilevel coding scheme with pseudo space-time trellis codes as component codes. The resultant MLPSTTC symbols generated at each cooperating node are transmitted to the common destination node through independent fading channels. Thus, the destination node receives multiple copies of information of each mobile node. The received coded signal at the destination node is passed through a multistage Viterbi decoder to detect the information of each mobile node. The performance of proposed cooperative multilevel pseudo space-time trellis coding technique is superior to most of the existing MLSTTC techniques.