Indoor throughput and range improvements using standard compliant AP antenna diversity in IEEE 802.11a and ETSI HIPERLAN/2

This paper explores the application of space-time diversity techniques to enhance the performance of 5 GHz WLAN. The analysis is based on systems conforming to either the IEEE 802.11a or ETSI HIPERLAN/2 standard. Two antennas are assumed at the access point (AP) with a single antenna at the mobile terminal (MT). Downlink (DL) improvements are offered via the application of one of two fully compliant diversity schemes. The first technique can be applied to time division duplex (TDD) OFDM systems (ie, HIPERLAN/2) and is based on adaptive sub-band phase compensation. The second technique can be applied to non-TDD systems (ie, 802.11a) and makes use of spatial transmit delay diversity. Uplink (UL) improvement is offered via the use of spatial receive diversity with maximal ratio sub-band combining. Software simulated physical (PHY) layer packet error rate (PER) results are presented for the various methods and compared with those of an unaided transceiver. Combining the enhanced link level results with an analysis of the 802.11a and HIPERLAN/2 protocols, the expected throughput and range enhancements for both standards are computed.