Research On The Performance Of GFDM With Index Modulation

Generalized frequency division multiplexing(GFDM)is a non-orthogonal multi-carrier modulation scheme.Considering a series of advantages that index modulation(IM)technology can bring to it,generalized frequency division multiplexing with index modulation(GFDM-IM)research has gradually become widespread.GFDM-IM has the advantages of high spectral efficiency and good peak to average power ratio performance.However,as a result of the non-orthogonal characteristics between adjacent sub-carriers in it,it will bring about large inter-carrier interference and deteriorate its bit error performance.At the same time,index detection will also increase the complexity of the receiving end.With regard to the above shortcomings,this paper will start from two aspects of improving the transmission reliability of GFDM-IM and reducing the complexity of index detection,mainly including the following contents.First,the basic principles of GFDM modulation and demodulation and IM modulation detection are introduced,and then combined,the transceiver model of the GFDM-IM system is given,and its bit error performance is simulated and compared with that before the combination.Secondly,in order to eliminate the interference caused by the non-orthogonality of the system,the dual-filte technology is applied to it,and a dual-filter GFDM-IM(DF-GFDM-IM)system is proposed.By redesigning the filter of GFDM,the odd and even carriers are orthogonal to each other,so as to eliminate the interference caused by adjacent subcarriers.Then,the bit error performance,reception complexity and out of band characteristics of the system before and after the application of dual filter technology are compared and analyzed.Next,in order to further improve the bit error performance of the GFDM-IM,a scheme of generalized frequency division multiplexing with hybrid number and reuse combination index modulation(GFDMHNRC-IM)is proposed.This scheme increases the number of index bits by reusing the index combination and increasing the index bits to control the number of activated subcarriers,and finally improves the bit error performance with the same spectral efficiency.At the same time,a low-complexity detection algorithm is designed for this purpose.The actual multiplication amount,spectral efficiency and bit error rate under multipath Rayleigh fading channel are simulated and verified.Finally,a joint simulation of the above two improvement measures is carried out.The simulation proves that the combined system has a greater improvement in the bit error performance.