Experimental Investigation of Four Transmit Antenna Space-Time Block Codes

Space-time trellis and space-time block codes harness the effects of spatial diversity by taking advantage of multiple independently fading transmit and receive antenna paths between the transmitter and receiver. In this paper, we present experimental studies primarily on the performance of four transmit antenna space-time block codes which, although promising in simulations, need to be investigated in real-world wireless channels. Simulations often inaccurately model the wireless channel impulse response and other impairments such as interference, signal fading, multipath, phase noise, etc. Experimental results reveal an improvement in reliability by use of space-time block codes as predicted in simulations. However, the theoretical diversity gains promised in the simulations cannot be fully realized because of what is believed to be interference generated by other RF sources on the same 2.4GHz WLAN band on which the experiments were conducted