The IEEE 802.11 System with Multiple Receive Antennas

Abstract

The demand for wireless local area networks (WLANs) based on the IEEE 802.11 standard is growing rapidly. These WLANs operate in the unlicensed spectrum, are relatively low-cost and provide very high data rates. The IEEE 802.11 system makes use of a carrier-sensing technique and packet collisions occur because the stations in a system are essentially uncoordinated. Packet collisions increase with the number of stations in the system and the traffic intensity. In this chapter, we examine the IEEE 802.11 system with multiple receive antennas. Multiple receive antennas can successfully detect multiple packets and thus reduce packet collisions. Also, multiple receive antennas help to reduce the packet errors due to channel errors. We analyze the IEEE 802.11 system with multiple antennas and propose some minor changes to the protocol to obtain the improved performance gains. It is shown that significant performance gains can be obtained using this system, for example, the throughput obtained with 10 stations and a single receive antenna is about 0.50; with two and three antennas the corresponding throughput increases to about 0.85 and 1.3, respectively.KeywordsSlot TimeMedium Access ControlDestination StationWireless Local Area NetworkContention WindowThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.