Walsh-Hadamard-Fourier transform based OFDM with space-multipath diversity

Walsh-Hadamard-Fourier transform based orthogonal frequency division multiplexing (WHFT-OFDM) is an efficient linearly precoded OFDM system to exploit multipath diversity in the frequency selective fading channel. This paper proposes a WHFT-OFDM scheme with space-multipath diversity by using the cyclic delay diversity (CDD) technique which deliberately introduces delayed echoes at transmitter to enhance the diversity gain of WHFT-OFDM. Moreover, the proposed WHFT-OFDM system provides an efficient way to implement the multicarrier code division multiple access for multiuser systems; its maximum multipath diversity, which is equal to the number of resolvable paths from the channels, is analyzed. Simulations are provided to validate the advantages of the proposed scheme.