On Transmit Diversity and Scheduling in Wireless Packet Data

Downlink time division multiplexing is considered for cellular packet-switched systems, in conjunction with scheduling algorithms for fast packet switching across the served users. Additionally, open and closed loop transmit diversity techniques at the base station are considered ti improve the spectral efficiency of the resulting system. A study is conducted on the effect of various transmit diversity techniques on the overall network data throughput in the presence of scheduling. Contrary to the circuit-switching paradigm, the presented results highlight the conflicting objectives of specific transmit diversity schemes and efficient scheduling. Characteristics of the transmit diversity schemes are identified that support their co-existence with greedy scheduling algorithms in improving the network data throughput.