Spectral-Efficiency Comparison of Multicell DS-CDMA/SDMA Systems with/without Base-Station Cooperation

In this contribution, we study the spectral-efficiency of uplink direct-sequence code-division multiple-access (DS-CDMA) and space-division multiple-access (SDMA) systems, which are operated in a double-cell scenario experiencing intercell interference. Our focus is on comparison of the achievable spectral-efficiency, when various base-station (BS) cooperation strategies and detection schemes are employed. Specifically, three BS operational schemes are considered, namely the ideal BS cooperation, data exchange only and no BS cooperation, in conjunction with four multiuser detection (MUD) schemes, including the optimum MUD (OMUD), OMUD with parallel interference cancellation (OMUD-PIC), linear minimum mean-square error MUD (MMSE-MUD) and the MMSE-based successive interference cancellation (MMSE-SIC). The impacts of system load, signal-to-noise ratio (SNR) and intercell interference strength on the achievable spectral-efficiency of the DS-CDMA and SDMA systems employing the above-mentioned BS cooperation and MUD schemes are investigated. Considering the trade-off between complexity and performance, our studies show that the MMSE-SIC aided by data exchange between BSs may constitute a promising multicell processing (MCP) scheme.