Investigation of channel estimation method for adaptive antenna array transmit diversity in W-CDMA forward link

摘要

This paper investigates an accurate channel estimation method using the common pilot channel (CPICH) in addition to a dedicated pilot channel when a fading correlation between the dedicated PICH and CPICH is high, and clarify the area in which the proposed channel estimation method is effective for adaptive antenna array transmit diversity (AAA-TD) in the forward link. Computer simulation results elucidate that although the more precise channel estimation is possible by using the primary-CPICH (P-CPICH) transmitted from omni-directional antenna in addition to the dedicated pilot channel for the area where the distanced between a base station and a mobile terminal is longer than approximately 200m, no improvement is obtained for the area where the value of d is shorter than approximately 200m. Meanwhile, by employing the secondary-CPICH (S-CPICH) transmitted with several directional beams in addition to the dedicated pilot channel, the required average received E{sub}b/N{sub}0 at the average BEE of 10{sup}(-3) is decreased by approximately 0.4 (0.2-0.4) dB compared to the channel estimation method using only the dedicated pilot channel regardless of the value of d when the number of antenna is 4 (8).