Multilevel space–time trellis coded cooperation with channel state information at transmitter

Abstract

SUMMARYIn this paper, the authors propose a system where a number of cooperating mobile nodes transmit information to a common destination node. Each cooperating node has a set of decoders to detect the information of other nodes and a set of encoders to further encode the decoded information as well as its own information using multilevel space-time trellis coding (MLSTTC) scheme. The coded information is mapped using multi-resolution modulation partitioning to M-ary quadrature amplitude modulation constellation. The mapped symbols are weighted based on the available channel state information at transmitting nodes. The weighting of transmitting symbols provides beamforming resulting in receive signal-to-noise ratio gain. The weighted symbols are sent to destination node through two transmit antennas. If the information of other nodes has been correctly decoded at the cooperating node, then the destination node receives the information of each node as many times as there are number of transmitting nodes, thus achieving full diversity order. A multistage Viterbi decoder is used at the destination node to extract information of each mobile node. The results indicate that the performance of proposed cooperative MLSTTC system is superior to non-cooperative MLSTTC system.

Posture-Specific Breathing Detection

“…The purpose of data processing is to denoise the original data representing the Y matrix using several common methods for electromagnetic wave denoising to determine whether the results meet the expected conditions. Previous studies [14,15,16,17,18] showed that, among the several traditional methods, wavelet transform has the best filtering effect. Therefore, in this process, wavelet transform was chosen.…”