Abstract: A method and apparatus for signal acquisition in an OFDM receiver relies on a preamble training sequence to synchronize the receiver in time (e.g. determining the start of a frame) and in frequency (carrier frequency offset compensation). The preamble training sequence has a periodic structure and the method and apparatus perform a cross-correlation technique using a matched filter to achieve time synchronization and/or frequency synchronization and/or channel estimation, the latter being especially useful in multi-antenna receivers for diversity combining purposes. Many advantages derive from performing at least two and preferably all three operations jointly, in terms of latency, hardware complexity, and length of training sequence required to achieve satisfactory convergence on all counts. The periodicity of the training sequence is exploited to reduce considerably the main filter complexity and optionally dynamically adjust carrier offset compensation throughout the filtering process.

Abstract: A method and apparatus for signal acquisition in an OFDM receiver relies on a preamble training sequence to synchronize the receiver in time (e.g. determining the start of a frame) and in frequency (carrier frequency offset compensation). The preamble training sequence has a periodic structure and the method and apparatus perform a cross-correlation technique using a matched filter to achieve time synchronization and/or frequency synchronization and/or channel estimation, the latter being especially useful in multi-antenna receivers for diversity combining purposes. Many advantages derive from performing at least two and preferably all three operations jointly, in terms of latency, hardware complexity, and length of training sequence required to achieve satisfactory convergence on all counts.

Abstract: An array receiver which reduces complexity and cost by exploiting multiuser information in signals received from a plurality of transmitting users preprocesses (40) samples of antenna signals (x1, x2 . . . , xN) from the antenna elements (22/1, . . . , 22/N) to form basis signals (yO, . . . , yM) together having fewer space-time dimensions than the space-time dimensions of the combined antenna signals. The receiver processes and combines the basis signals to produce sets of estimated received signals (z0, . . . , zM), each for a corresponding one of the users. Each of the basis signals comprises a different combination of the antenna signals. The receiver combines the basis signals to provide a user-specific output signal, and periodically updates parameters of the filters (40/0, . . . , 40/M) used for deriving each particular basis signal such that each user-specific output signal will exhibit a desired optimized concentration of energy of that user's received signal as received by the array antenna.

Abstract: An array antenna system comprising an array of antenna elements and a receiver which uses a subset of the signals from the antenna elements, the selection of the subset of signals which should be used for a particular user is made on the basis of measurements of potential performance of the receiver with each subset of signals, combined, rather than of each individual signal.

Abstract: An array antenna system comprising an array of antenna elements and a receiver which uses a subset of the signals from the antenna elements, the selection of the subset of signals which should be used for a particular user is made on the basis of measurements of potential performance of the receiver with each subset of signals, combined, rather than of each individual signal.