Field trial results for high-speed wireless indoor data communications

This paper reports on the development of a flexible 5-MBd equalized M-QAM t estbed for high-speed wireless data communications, The unit operates in re al time and was held tested in typical indoor environments. A total of 3600 independent experiments were conducted using the testbed where one of 4-, 16-, 64-QAM constellations were transmitted, and the performance as a funct ion of adaptive equalization and antenna selection diversity was studied. T he experimental results presented here help put previous simulation and ana lytical results into perspective and demonstrate some of the performance bo unds associated with a practical implementation. The field trial results sh ow that with only 10-mW of transmit power, reliable 10-Mbit/s data communic ation can take place in between rooms with a coverage radius of 17 m, and b etter than 15% outage at an uncoded bit error rate (BER) of 10(-3). The add ition of two-branch antenna selection diversity to the system would allow 1 0-Mbit/s transmission at better than 3% outage and 20-Mbit/s transmission a t 10% outage in the same environment. Moreover, 30-Mbit/s data transmission is feasible when both the transmitter and receiver are located within the same room, albeit at higher outage levels, In general, the results demonstr ate the tremendous impact that adaptive equalization can have on the achiev able performance of indoor links. Average SNR was improved anywhere from 8 dB to 12 dB depending on the particular environment and data rate. The impa ct on the outage performance, however, was much more dramatic.