MIMO-MC-CDMA System Uplink: Single-User vs Multi-User Detection Algorithm Comparison

In the uplink of MIMO-MC-CDMA systems, we conduct a comparative study of different detection algorithms for both single-user and multi-user scenarios. Initially, we investigate and analyze detection algorithms for single-user cases, which typically involve algorithms like Maximum Likelihood (ML) detection or Zero-Forcing (ZF) equalization implemented through matrix inversion operations. These algorithms can be coded using mathematical operations on channel matrices, where the received signal vector y is processed as y = Hx + n, with H representing the channel matrix, x the transmitted signal, and n the noise vector.

Subsequently, we explore multi-user detection algorithms, which include techniques such as Minimum Mean Square Error (MMSE) detection, Successive Interference Cancellation (SIC), and Parallel Interference Cancellation (PIC). These algorithms require more complex computational implementations, often involving iterative processing and covariance matrix calculations to mitigate multiple access interference. The MMSE detector, for instance, can be implemented using the formula W = (H^H H + σ²I)^{-1}H^H, where σ² represents the noise variance and I is the identity matrix.

Through systematic comparison of these algorithms using performance metrics like Bit Error Rate (BER) and computational complexity analysis, we gain deeper insights into their performance differences in MIMO-MC-CDMA systems. This analysis provides valuable guidance for system optimization and enhancement, particularly in algorithm selection based on specific implementation constraints and quality-of-service requirements.