| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide calibration of downlink and uplink to account for differences in the responses of transmit and receive chains at an access point and a user terminal. <P>SOLUTION: For initial calibration, the access point and user terminal transmit MIMO pilots, which are used to derive channel estimates including the responses of the applicable transmit/receive chains, on the downlink and uplink. Correction matrices are derived based on these channel estimates, and thereafter they are used by the access point and user terminal, respectively. For follow-on calibration, one entity transmits the MIMO pilot and a steered reference. The other entity derives a first transmit matrix based on the steered reference, and a second transmit matrix based on the MIMO pilot and calibration error matrices which contain estimates of the errors. The calibration error matrices may be iteratively adjusted based on an adaptive procedure to minimize the errors between the two transmit matrices. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
