Characterization of 29.5 GHz broadband indoor radio channels using a steerable receive antenna

by Hendrantoro, Gamantyo

The work reponed in this thesis sought to investigate the characteristics, in ternis of parameters such as the channel delay spread and the received power, of broadband millimeterwave indoor radio channels when at both the transmitter and the receiver a directional antenna is employed. It was also of great interest to study the effea of the variation in reception angle on these characteristics. The result of this study is significant in designing transmission systems suitable for broadband mm-wave wireless communication systems deployed indoors. Four rooms in several buildings on the Carleton University campus were selected as experirnental sites, one of which was a haliway while the rest were of rectangular shape. A spread-spectrum based channel measurement system was adopted, using a 1023-bit pseudonoise sequence generated at 200 Mbps and aansrnitted over a 29.5 GHz camerwave using a biphase modulation process. A 30'-beamwidth hom antenna was employed at the transmitter, while the receive antenna was a programmable phaseci-array antenna of 8' bearnwidth. Field measurements were accomplished by acquiring complex envelope sarnples of the received signal and the received power for each of eleven rezeption angles, that range fiom -30' to 30' with 6' spacings in between, programmed on the receive antenna controller. The charme1 impulse response eshates were obtained afterward by crosscorrelating the measured complex envelope and a replica of the original sequence. The main results £rom the analyses include that with directional antennas of the same mes as ours at both sides of the luik, (i) high suppression of interferences coming from angles different than that of the direct path is achieved while mahg the received power sensitive to antenna rnisalignrnent, (ii) rnultipath delay spread is infiuenced by the room dimension dong which the nansmission link exists while its angledependent behavior is affected by the antenna characteristics, (fi) an angular difference of 6' between two branches of an angle diversity system is sufncient to yield a low correlation, and (iv) the average received power decreases as the inverse n " power of the propagation range, where the exponent n is on the order of 0.93, when both antennas are alignai.