MIMO/Transmit Diversity Channel Estimation

A receive station in a MIMO communication system, the receive station comprising:

• a receiver front end to receive a signal comprising a combination of multiple pilot signals from different transmit antennas in the MIMO communication system;
• a despreader configured to:
• despread the received signal over an extended period comprising multiple symbol periods using mutually orthogonal extended spreading sequences for the pilot signals to obtain a first set of despread signals over the extended period;
• and
• despread the received signal over each symbol period of said extended period using a common spreading sequence to obtain a second set of despread pilot signals over each symbol period of the extended period;
• a signal processor configured to:
• determine average channel estimates for the pilot signals over the extended period based on the first set of despread pilot signals;
• determine combined channel estimates for the pilot signals over each symbol period of the extended period based on the second set of despread signals;
• and
• determine individual channel estimates for the pilot signals over each symbol period of the extended period based on the average channel estimates and the combined channel estimates.

A channel estimation unit in a receive station of a MIMO communication system, wherein the receive station receives a signal comprising a combination of multiple pilot signals from different transmit antennas in the MIMO communication system, said channel estimation unit comprising:

• a despreader configured to:
• despread the received signal over an extended period comprising multiple symbol periods using mutually orthogonal extended spreading sequences for the pilot signals to obtain a first set of despread signals over the extended period;
• and
• despread the received signal over each symbol period of said extended period using a common spreading sequence to obtain a second set of despread pilot signals over each symbol period of the extended period;
• a signal processor configured to:
• determine average channel estimates for the pilot signals over the extended period based on the first set of despread pilot signals;
• determine combined channel estimates for the pilot signals over each symbol period of the extended period based on the second set of despread signals;
• and
• determine individual channel estimates for the pilot signals over each symbol period of the extended period based on the average channel estimates and the combined channel estimates.