Research On Recursive Overlapped Time Division Multiplex-ing And Its Combination With Cooperative Communication

In wireless networks, cooperation communication is a novel technology that uses otheruser’s idol antenna to obtain the spatial diversity gain and improve the system capacity.Overlapped Time Division Multiplexing(OVTDM) improves the spectral efficiency byoverlapping the time domain signal. This paper mainly studied the performance of recursiveoverlapped time division multiplexing and its application in cooperative communication.Firstly, OVTDM, recursive OVTDM(ROVTDM), and parallel concatenated scheme forROVTDM(P-ROVTDM) are introduced. The performance of P-ROVTDM system is muchbetter than OVTDM and ROVTDM with the same overlapped number.Secondly, combine OVTDM and ROVTDM with amplify-forward(AF) cooperative relayand decoded-forward(DF) cooperative relay, respectively. Experiments show that theperformance of these new systems is better than that of the AF and the DF system under thesame spectrum efficiency. The performance of the systems with different recursive coefficientmatrix are also discussed, the results show that the fully recursive system is slightly betterthan the non-recursive one when the SNR is high, and other recursive systems is all worsethan the non-recursive system, but the difference is slight.Finally, the performance of systems which combined P-ROVTDM with AF and DF aremuch better than the systems which combined OVTDM、ROVTDM with AF and DF. Notonly the spectrum efficiency improves greatly, but also the SNR reduces a lot for the sameBER(bit error rate). The paper analysis different interleaver’s influence on the performance ofnew system,because of the great influence of interleave on performance in P-ROVTDMsystem. Simulation results show that the performance of the system using S-interleaver isrelatively better.