Abstract: Methods and systems for operating a base station communicating with one or more user terminals in an orthogonal frequency division multiple access (OFDMA) system where the one or more user terminals are configured to insert pilots in up stream bursts every nth symbol on each subcarrier, where n is an integer, are provided. The method includes identifying a needed amount of up stream bandwidth to be allocated to a user terminal; determining the subcarriers and the number of symbols per subcarrier to be allocated to meet the identified need in a burst; allocating, for the user terminal, a set of subcarriers and a number of symbols for each member of the set of subcarriers, wherein sufficient symbols per subcarrier per burst are allocated to allow user terminal to send two or more pilots per subcarrier per burst; and transmitting a message to the user terminal, the message identifying the allocated subcarriers and the number of symbols allocated for each subcarrier.

Abstract: Methods and systems which include identifying a needed amount of US bandwidth to be allocated to a user terminal; determining the subcarriers and the number of symbols per subcarrier to be allocated to meet the identified need in a burst; allocating, for the user terminal, a set of subcarriers and a number of symbols for each member of the set of subcarriers, wherein sufficient symbols per subcarrier per burst are allocated to allow user terminal to send two or more pilots per subcarrier per burst; and transmitting a message to the user terminal, the message identifying the allocated subcarriers and the number of symbols allocated for each subcarrier.

Abstract: The present invention comprises systems, methods, and devices for detecting the presence of a specified signal type by autocorrelating the signal with a time-delayed copy of itself, by simultaneously crosscorrelating the signal with an expected signal type, and by then comparing the results of the autocorrelation and crosscorrelation to determine whether or not the signal is present and to ascertain its type.

Abstract: The present invention comprises systems, methods, and devices for detecting the presence of a specified signal type by autocorrelating the signal with a time-delayed copy of itself, by simultaneously crosscorrelating the signal with an expected signal type, and by then comparing the results of the autocorrelation and crosscorrelation to determine whether or not the signal is present and to ascertain its type.

Abstract: Digital signals transmitted on an RF carrier modulated in phase and amplitude and subject to noise constitute separate bursts each comprising information symbols of data and a pair of separated unique words. The signals are subjected to processing which involves reception of the signals and an initial conversion to approximate baseband and then analog to digital sampling. Quadrature and in phase samples are then stored in a buffer. The buffered samples are subjected to coarse timing, coarse frequency synchronization, a first phase correction, fine timing, further phase and amplitude correction and finally to fine frequency correction and subsequent reliability estimation.