A single transmitter transmits K communication bursts in a shared spectrum in a time slot of a time division duplex communication system. Each burst has an associated midamble sequence, a receiver knowing the midamble sequences of the K bursts. The receiver receives a vector corresponding to the transmitted midamble sequences of the K communication bursts. A matrix having K right circulant matrix blocks is constructed based in part on the known K midamble sequences. The wireless channel between the transmitter and receiver is estimated based on in part the K block matrix and the received vector.
This application is a continuation of U.S. patent application Ser. No. 11/217,960, filed Sep. 1, 2005 now U.S. Pat No. 7,103,092, which is a continuation of U.S. patent application Ser. No. 09/755,400, filed on Jan. 5, 2001, which issued as U.S. Pat. No. 6,985,513, which claims priority from U.S. Provisional Patent Application No. 60/175,167, filed on Jan. 7, 2000; all of which are incorporated by reference herein.
