Throughput and Channel Access Statistics of Generalized Selection Multiuser Scheduling

To provide a near-optimal low-complexity solution to parallel multiuser scheduling in code-division multiple-access (CDMA), we propose generalized selection multiuser diversity (GSMuD) schemes with multi-code channel assignment and analyze their performance. The proposed GSMuD (L_c, L) schemes rank a total of L users awaiting transmissions by their signal-to- noise ratios (SNRs) and select the L_c (1les Lc les L) users with the largest absolute (or normalized) SNRs for parallel channel access, which achieve near-optimal sum rate with a low scheduling complexity. The sum and individual channel throughput rates, second order statistics, fairness, and channel access statistics of the proposed GSMuD schemes are derived, taking into account different types of generalized fading channels. Compared to the round robin (RR) scheduling without SNR ranking, the GSMuD with normalized SNR ranking achieves a substantially higher sum rate while maintaining fairness. GSMuD also significantly improves the channel access performance and the degree of fairness than selective multiuser diversity (SMuD), which selects one best user only at each time slot.