To provide techniques to calibrate downlink and uplink channels to account for differences in frequency responses of transmission and reception chains at an access point and a user terminal.
Pilots are transmitted on downlink and uplink channels and used to derive estimates of downlink and uplink channel responses, respectively. Two sets of correction factors are then determined based on the estimates of the downlink and uplink channel responses. A calibrated downlink channel is formed by using a first set of correction factors for the downlink channel, and a calibrated uplink channel is formed by using a second set of correction factors for the uplink channel. The first and second sets of correction factors may be determined using a matrix-ratio computation or a minimum mean square error (MMSE) computation. The calibration may be performed in real time based on over-the-air transmission.
KETCHUM JOHN W
WALTON J RODNEY
HOWARD STEVEN J
| JP2002514033A | 2002-05-14 | |||
| JP2001510668A | 2001-07-31 |
Satoshi Kono
Makoto Nakamura
Yoshihiro Fukuhara
Takashi Mine
Toshio Shirane
Sadao Muramatsu
Nobuhisa Nogawa
Kocho Chojiro
Naoki Kono
Katsu Sunagawa
Katsumura Hiro
Tatsushi Sato
Takashi Okada
Mihoko Horiuchi
Takenori Masanori
Takuzo Ichihara
Yamashita Gen