Low complexity GFDM receiver design: A new approach

GFDM (Generalized Frequency Division Multiplexing) is a multicarrier modulation technique that is being proposed as a potential candidate for the fifth generation of wireless communication systems (5G). Due to the fact that GFDM uses only one cyclic prefix (CP) for a group of symbols rather than a CP per symbol and it has a well contained spectral properties, it is more bandwidth efficient than the widely used OFDM modulation. In this paper, we propose novel receiver designs for GFDM by taking advantage of the particular structure in the modulation matrix. A unified receiver structure for matched filter (MF), zero forcing (ZF) and minimum mean square error (MMSE) receivers is derived. Our proposed MF receiver is based on sparsification of the modulation matrix using block discrete Fourier transform (DFT) matrix. The proposed ZF and MMSE receiver algorithms in this paper harness the special block circulant property of the matrices involved in the demodulation stage to reduce the computational cost of the system implementation. In addition, our algorithms do not incur any performance loss as no approximation is involved. The computational costs of our proposed techniques are analyzed in detail and are compared with the existing solutions that are known to have the lowest complexity. It should be highlighted that a substantial computational complexity reduction can be achieved by adopting our techniques.