Abstract: A method of transmitting data signals from at least two transmitting terminals to at least one receiving terminal with a spatial diversity antenna comprises transmitting from the transmitting terminals transformed data signals, being transformed versions of the data signals; receiving on the spatial diversity means received data signals being at least function of at least two of the transformed data signals; subband processing of at least two of the received data signals in the receiving terminal; and determining estimates of the data signals from subband processed received data signals in the receiving terminal.

Abstract: Various methods and apparatus for frequency-domain estimation of carrier frequency offsets are provided in which the carrier frequency offset estimate is robust against non-white (frequency-dependent) noise. A carrier-specific weighting factor is associated with each carrier of a multi-carrier signal. Using the carrier-specific weighting factors, a carrier frequency offset estimate is computed from received signals and estimated channel transfer functions associated with each of the carriers. Because greater weights are given to carriers whose frequencies include lower noise and/or carriers transmitting a known sequence of symbols, the estimate of the carrier frequency offset is improved. The carrier frequency offset estimate may then be applied in a feedback loop to phase-compensate a subsequently received signal.

Abstract: Various methods and systems efficiently implement broadband multi-carrier communication systems. The invention exploits the structural properties of a frequency-domain channel estimator and transforms it into the time domain. This allows the sharing of certain blocks of hardware (e.g., matched filters otherwise used for timing acquisition) which results in significant reduction of complexity.

Abstract: This invention relates to a method and apparatus for channel estimation. A method of determining a maximum likelihood frequency domain estimate of the channel response of a channel between at least one transmitting peer and at least one receiving peer, said method comprising transmitting NU reference tones from said transmitting peer to said receiving peer; capturing said NU reference tones at said receiving peer; and determining at said receiving peer from said NU reference tones said maximum likelihood frequency domain estimate of said channel response at NF predetermined frequencies by directly exploiting the finiteness of the time response of said channel.