MIMO broadcasting with delay-constrained and no-delay-constrained services

This paper studies the system throughput limits of the MIMO broadcast channel for wireless downlink transmission. More specifically, the expected throughput for no-delay-constrained (NDC) traffic and the delay-limited throughput for delay-constrained (DC) traffic are characterized and compared. The multiuser-diversity effect on the delay-limited throughput for DC traffic is discussed for the first time. A novel transmission scheme that can simultaneously support both NDC and DC traffics is proposed. Computer simulation shows that the proposed scheme can approach the system throughput limit effectively provided that it is designed for the correct traffic ratio between NDC and DC services.