Research On Signal Detection Algorithm For MIMO-GFDM System

Generalized Frequency Division Multiplexing(GFDM)is a flexible digital multicarrier modulation scheme.The flexibility of GFDM can meet different application requirements of future networks.Multiple input multiple output(MIMO)technique can improve the capacity of the communication system without additional transmission power and system bandwidth.MIMO-GFDM takes advantages of the good features of MIMO and OFDM to provide better system performance.The main contents are organized as follows:Firstly,the fundamental principle of GFDM has been studied and analyzed.A comparative analysis and simulation results between GFDM and OFDM have also been given.And introducing the concepts of the MIMO technology briefly.Then a MIMO channel modeling has been presented.Secondly,two schemes are studied: STC-GFDM and TR-STC-GFDM,which combined GFDM with STC and TR-STC respectively.In addition,the basic principles of coding and decoding for two schemes have been analyzed,and introduction of the Walsh-Hadamard transform and Discrete W transform improves the system performance.Simulation results show that WHT/DWT-STC-GFDM can achieve better performance than STC-OFDM.Finally,the signal detection algorithm of GFDM systems,including zero-forcing(ZF),minimum mean square error(MMSE),QR decomposition and Lattice Reduction-Aided(LRA)have been studied.The detection performance of ZF and MMSE is poor,so the combination of MMSE with LR has been presented to enhance the system performance significantly.Moreover,the serial interference cancellation technology based on the QR decomposition is incorporated in LRA-MMSE and leads to a performance improvement further.The computer simulation results show that LRA detectors are more robust to spatial correlation compared to traditional detectors.