Abstract: A modem is configurable on a satellite, user terminal or gateway generates a radio frequency (RF) signal using an orthogonal frequency division multiplexing (OFDM) protocol including a radio frame including one or more bursts. A burst of the one or more bursts includes a first portion including burst detection data, a second portion including channel characteristic estimation data, a third portion including payload data, and fourth and fifth portions including pilot data. The first portion in a time domain is included in the burst prior to the second, third, fourth, and fifth portions. The first portion can include a pseudo-random noise sequence inserted in the time domain. The same physical modem can be configured to transmit signals on an uplink or downlink between a user terminal and a satellite or on the uplink or downlink between the satellite and the gateway.

Abstract: A modem is configurable on a satellite, user terminal or gateway generates a radio frequency (RF) signal using an orthogonal frequency division multiplexing (OFDM) protocol including a radio frame including one or more bursts. A burst of the one or more bursts includes a first portion including burst detection data, a second portion including channel characteristic estimation data, a third portion including payload data, and fourth and fifth portions including pilot data. The first portion in a time domain is included in the burst prior to the second, third, fourth, and fifth portions. The first portion can include a pseudo-random noise sequence inserted in the time domain. The same physical modem can be configured to transmit signals on an uplink or downlink between a user terminal and a satellite or on the uplink or downlink between the satellite and the gateway.

Abstract: A modem is configured to receive a transmitted waveform transmitted from a satellite (SAT) to a user terminal (UT). The modem includes: a receiver, on the UT, configured to receive the transmitted waveform from the SAT, the transmitted waveform comprising first resource blocks intended for the UT and second resource blocks intended for a second UT, a first set of components configured with the receiver on the UT to process the transmitted waveform with the first resource blocks and the second resource blocks, a multi-user demapper configured with the receiver to extract the first resource blocks from the transmitted waveform to yield a per-user signal, and a second set of components configured within the receiver to demodulate and decode the first resource blocks in the per-user signal.

Abstract: A modem is configurable on a satellite, user terminal or gateway generates a radio frequency (RF) signal using an orthogonal frequency division multiplexing (OFDM) protocol including a radio frame including one or more bursts. A burst of the one or more bursts includes a first portion including burst detection data, a second portion including channel characteristic estimation data, a third portion including payload data, and fourth and fifth portions including pilot data. The first portion in a time domain is included in the burst prior to the second, third, fourth, and fifth portions. The first portion can include a pseudo-random noise sequence inserted in the time domain. The same physical modem can be configured to transmit signals on an uplink or downlink between a user terminal and a satellite or on the uplink or downlink between the satellite and the gateway.

Abstract: A modem is configurable on a satellite, user terminal or gateway generates a radio frequency (RF) signal using an orthogonal frequency division multiplexing (OFDM) protocol including a radio frame including one or more bursts. A burst of the one or more bursts includes a first portion including burst detection data, a second portion including channel characteristic estimation data, a third portion including payload data, and fourth and fifth portions including pilot data. The first portion in a time domain is included in the burst prior to the second, third, fourth, and fifth portions. The first portion can include a pseudo-random noise sequence inserted in the time domain. The same physical modem can be configured to transmit signals on an uplink or downlink between a user terminal and a satellite or on the uplink or downlink between the satellite and the gateway.

Abstract: A modem is configurable on a satellite, user terminal or gateway generates a radio frequency (RF) signal using an orthogonal frequency division multiplexing (OFDM) protocol including a radio frame including one or more bursts. A burst of the one or more bursts includes a first portion including burst detection data, a second portion including channel characteristic estimation data, a third portion including payload data, and fourth and fifth portions including pilot data. The first portion in a time domain is included in the burst prior to the second, third, fourth, and fifth portions. The first portion can include a pseudo-random noise sequence inserted in the time domain. The same physical modem can be configured to transmit signals on an uplink or downlink between a user terminal and a satellite or on the uplink or downlink between the satellite and the gateway.

Abstract: Various embodiments of techniques related to interference cancellation in wireless OFDMA with MIMO spatial multiplexing are provided. In one aspect, a method receives wireless communication downlink signals from a first base station and a second base station. The method cancels interference of wireless downlink communications between the first base station and the communication device by the second base station by calculating an equalizer solution that orthogonalizes the downlink signals from the first and the second base stations.

Abstract: Various embodiments of techniques related to sample clock timing acquisition are provided. In one aspect, a method includes a first communication device receiving a wireless communication signal from a second communication device. The method also includes detecting a primary synchronization signal in the wireless communication signal. The method further includes estimating, based at least in part on the primary synchronization signal, a frequency offset between a sample clock timing frequency of the first communication device and a sample clock timing frequency of the second communication device.

Abstract: Various embodiments of a transmit diversity decoding techniques are provided. In one aspect, a method receives a first input that includes signals transmitted by M transmit antennas on C channels and received by N receive antennas, where M, N and C is each a positive integer greater than 1. The method also receives a second input that includes estimates of channel matrix elements. The method further generates an output that includes at least an estimate of a transmit signal transmitted by one of the M transmit antennas on one of the C channels based at least in part on the first and the second inputs.

Abstract: Various embodiments of a transmit diversity decoding techniques are provided. In one aspect, a method receives a first input that includes signals transmitted by M transmit antennas on C channels and received by N receive antennas, where M, N and C is each a positive integer greater than 1. The method also receives a second input that includes estimates of channel matrix elements. The method further generates an output that includes at least an estimate of a transmit signal transmitted by one of the M transmit antennas on one of the C channels based at least in part on the first and the second inputs.

Abstract: Various embodiments of techniques related to interference cancellation in wireless OFDMA with MIMO spatial multiplexing are provided. In one aspect, a method receives wireless communication downlink signals from a first base station and a second base station. The method cancels interference of wireless downlink communications between the first base station and the communication device by the second base station by calculating an equalizer solution that orthogonalizes the downlink signals from the first and the second base stations.

Abstract: Various embodiments of primary synchronization signal detection are provided. In one aspect, a method receives one or more signals at one or more antennas of a receiver. The method processes the one or more received signals by decimation filtering the one or more received signals to provide one or more decimated signals, each of the one or more decimated signals having a predetermined symbol size, and enumerating correlation of the one or more decimated signals with a plurality of reference signals to provide correlation results. The method then detects a primary synchronization signal (PSS) based on the correlation results.

Abstract: Various embodiments of primary synchronization signal detection are provided. In one aspect, a method receives one or more signals at one or more antennas of a receiver. The method processes the one or more received signals by decimation filtering the one or more received signals to provide one or more decimated signals, each of the one or more decimated signals having a predetermined symbol size, and enumerating correlation of the one or more decimated signals with a plurality of reference signals to provide correlation results. The method then detects a primary synchronization signal (PSS) based on the correlation results.

Abstract: A communication system and method is disclosed that performs symbol boundary synchronization by generating a symbol alignment estimate from a partial signal correlation; and then refining the symbol alignment estimate via a carrier phase calculation. To generate the symbol alignment estimate, two methods are disclosed. After an estimate is determined, an embodiment provides for refining the symbol alignment estimate via a carrier phase calculation by determining a carrier phase of two adjacent carriers, determining a phase error as directly proportional to an offset from the start of a symbol, determining a phase difference contribution due to a communication channel and device hardware, and counter-rotating the determined carrier phase by an angle of a constellation point at a transmitter.

Abstract: Various embodiments of a transmit diversity decoding techniques are provided. In one aspect, a method receives a first input that includes signals transmitted by M transmit antennas on C channels and received by N receive antennas, where M, N and C is each a positive integer greater than 1. The method also receives a second input that includes estimates of channel matrix elements. The method further generates an output that includes at least an estimate of a transmit signal transmitted by one of the M transmit antennas on one of the C channels based at least in part on the first and the second inputs.

Abstract: A communication system and method is disclosed that performs symbol boundary synchronization by generating a symbol alignment estimate from a partial signal correlation; and then refining the symbol alignment estimate via a carrier phase calculation. To generate the symbol alignment estimate, two methods are disclosed. After an estimate is determined, an embodiment provides for refining the symbol alignment estimate via a carrier phase calculation by determining a carrier phase of two adjacent carriers, determining a phase error as directly proportional to an offset from the start of a symbol, determining a phase difference contribution due to a communication channel and device hardware, and counter-rotating the determined carrier phase by an angle of a constellation point at a transmitter.

Abstract: A multicarrier transceiver is disclosed that includes a digital signal processor with a plurality of memory locations, a direct memory, an encoder module coupled to receive data from the FIFO buffers, a decoder module coupled to receive data from the FIFO buffers, a Fourier transform module configured to perform an inverse Fast Fourier transform for transmit operations and to perform Fast Fourier transform (FFT) operations for receive operations, a plurality of distributed modules including the encoder module, the decoder module and the Fourier transform module, each module configured with a memory port, each memory port coupled to a peripheral bus and the DMA bus, a plurality of memory ports coupled to each of the distributed modules, the plurality of memory ports coupled to a peripheral bus, and a plurality of point-to-point buses coupled to each of the distributed modules, the point-to-point bus configured to enable data flow and testing and provide a bypass capability for each of the distributed modules.

Abstract: The system and method of the preferred embodiments may be directed to improving the signal-to-noise ratio in frequency spectrum regions where narrowband interference may be present. The system and method of the preferred embodiments includes reducing the narrowband interference by determining a noise estimate. In accordance with the noise estimate and output of a frequency domain equalizer, a noise-cancelled output may be obtained.

Abstract: A method and a device for providing timing recovery in a multicarrier transmission system is provided. The data derived timing recovery apparatus with the timing error controller adjusts the sampling rate at the receiver. The data derived timing recovery apparatus uses decision directed carrier phase errors to calculate a phase error. The timing error controller adjusts the sampling rate at the receiver in accordance with the phase error.

Abstract: A system and method for minimizing the effective channel impulse response in multitone communication systems, is provided. A time domain equalizer is utilized to shorten the channel impulse response to a length equal to or less than the time duration of the cyclic prefix. The time domain equalizer includes an adaptable filter with updateable coefficients. The updateable coefficients are calculated in a storage efficient manner to effectively estimate a desirable channel response. Processing of the time domain equalizer signal improves the symbol boundary estimate and effectively reduces the effect of noise of the updateable coefficient solution.