Patent ID: 8204143
Filing Date: 2012-06-19
Classification: H04B

Abstract:
1. A communication system, comprising: transmission baseband circuitry, which is coupled to produce first and second baseband signals with a first relative beamforming phase offset therebetween, the first baseband signal comprising a first sequence of first pilot symbols, and the second baseband signal comprising a second sequence of second pilot symbols, such that each first pilot symbol is transmitted concurrently with a corresponding second pilot symbol, wherein each of the first and second sequences comprises at least first and second interleaved sub-sequences, such that each of the first pilot symbols in the first sub-sequence has a first phase offset relative to the corresponding second pilot symbol, and each of the first pilot symbols in the second sub-sequence has a second phase offset, which is different from the first phase offset, relative to the corresponding second pilot symbol; first and second transmitters, which are respectively coupled to process the first and second baseband signals so as to produce and transmit first and second Radio Frequency (RF) signals; first and second receivers, which are respectively coupled to receive first and second combinations of the first and second transmitted RF signals and to produce respective first and second received signals; and reception baseband circuitry, which is coupled to combine the first and second received signals to produce a composite signal, to measure respective first and second magnitudes of the pilot symbols belonging to the first and second sub-sequences in the composite signal, to process the first and second magnitudes to compute a second relative beamforming phase offset, and to provide the second relative beamforming phase offset to the transmission baseband circuitry to correct an error included in the first relative beamforming phase offset.