Research On Detection Algorithm Of GFDM

Generalized frequency division multiplexing(GFDM)is a novel multi-carrier modulation.Compared with Orthogonal frequency division multiplexing(OFDM),GFDM has advantages of low peak-to-average ratio,low out-of-band radiation,high spectral efficiency and flexible waveform,etc.Therefore,GFDM can be better adapted to the future development of wireless communication networks.In this thesis,firstly,the structure and modulation principle of GFDM system are studied,according to the analysis,the modulation principle can be summarized into a matrix.Based on the modulation matrix,three linear receivers are studied,namely matched filter receiver(MF),zero-forcing receiver(ZF)and minimum mean square error receiver(MMSE).Then,to address the problem that MF receiver would amplify the ICI,which is self-generated by the system itself due to the inherent non-orthogonality of the subcarriers,a double sided serial interference cancellation procedure is studied,and the performance of several receivers are compared by simulation.Secondly,the detection algorithm of multi-input and multi output GFDM(MIMO-GFDM)is studied.MIMO-GFDM takes advantages of the good features of MIMO and GFDM to provide better system performance.However,the complexity of the minimum mean square error(MMSE)detection is prohibitively high.In order to improve BER performance in a manageable complexity,a signal detection and decoding algorithm based on expectation propagation(EP)for MIMO-GFDM coded systems is studied,which can remove inter-subcarrier interference(ICI),inter-symbol interference(ISI),and inter-antenna interference(IAI)at the same time.Futhermore,GFDM-IM system is studied and three different index modulation schemes in GFDM are proposed in this paper.The BER performance among using different linear receivers is compared by simulation.In order to optimize the BER,a message passing(MP)-based signal receiver is proposed by taking the activation pattern constraint into account in this paper.Then a sparse message passing(SMP)receiver based sparse modulation matrix is proposed,which has the ability to reduce complexity with negligible loss of BER performance.