Field experiments on adaptive antenna array-beam forming with simultaneous path timing and its DOA estimations employing directive-beam reception for broadband CDMA packet access in reverse link

This paper presents field experimental results on an adaptive antenna array-beam forming (AAA-BF) receiver with that uses simultaneous estimations of received timings and direction of arrivals (DOAs) of Rake combining paths employing directive beam reception based on a pilot channel-assisted two-dimensional power profile in the reverse link for broadband DS-CDMA packet wireless access. Laboratory experimental results elucidate that path-independent weight generation is superior to path-common weight generation based on the implemented AAA-BF receiver in a multipath Rayleigh fading channel with up to eight paths. The required average received signal energy per bit-to-background noise power spectrum density ratio (E_b/N₀) using path-common antenna weight generation is increased according to the increase in the angle spread among paths, σ, since the antenna gain toward the DOA of each path is reduced. Nevertheless, the increase in the antenna gain according to the number of antennas is achieved by using path-independent antenna weight generation regardless of the σ value up to 20 degrees. Furthermore, the field experimental results show that the required average received signal to interference plus background noise power ratio (SINR) at the average block error rate (BLER) of 10^-2 employing path-independent weight generation is reduced by approximately 3.5 dB compared to that using path-common weight generation for a large r.m.s. angle spread such as 9 degrees. In the field experiments, the required average received SINR at the average BLER of 10^-2 using the AAA-BF receiver with path-independent antenna weight generation is reduced by approximately 6.0 dB compared to that with one-antenna reception, regardless of the angle spread values.