Linear Dispersion Codes in Space-Frequency Domain for SCFDE: a General Framework

This paper presents a general framework for applying the Linear Dispersion Codes (LDC) in the space and frequency domains to Single Carrier - Frequency Domain Equalization (SCFDE) systems. Space-Frequency (SF)-LDC are more suitable than Space-Time (ST)-LDC in high mobility environment. However, the application of LDC in space- frequency domain in SCFDE systems is not straightforward as in Orthogonal Frequency Division Multiplexing (OFDM), since there is no direct access to the subcarriers at the transmitter. This paper describes how to build the space-time dispersion matrices to be used at the transmitter as a function of the desired dispersion matrices in the space and frequency domains. The performance comparison of SF-LDC and ST-LDC in a typical propagation environment for future radio systems confirms the suitability of using the dispersion in frequency instead of in time. The sensitivity of SF-LDC with respect to different levels of time and frequency selectivity is also shown.