Abstract: Systems and methods are described for performing Layered Belief LDPC decoding on received Standard Belief LDPC encoded data bursts. In on implementation, a receiver: demodulates a signal, the demodulated signal including a noise corrupted signal derived from a codeword encoded using standard belief LDPC encoding; converts the noise corrupted signal derived from the standard belief LDPC encoded codeword to a noise corrupted signal derived from a layered belief LDPC encoded codeword; and decodes the noise corrupted signal derived from the layered belief LDPC encoded codeword using a layered belief LDPC decoder. In further implementations, systems are described for reducing collisions in Layered Belief LDPC decoders that occur when multiple parity checks need the same soft decision at the same time. In these implementations, elements in an original LBD decoder table are rearranged to increase the distance between elements specifying the same location in a RAM where soft decisions are stored.

Abstract: Various methods and apparatuses are disclosed, including a method for optimizing FEC code for an average number of interfering users in a multiple access communication, that includes receiving an FEC code optimization information, switchable between at least a first value and a second value, and selecting a first optimized FEC code based at least in part on the FEC code selection information being at the first value, and selecting a second optimized FEC code based at least in part on the FEC code selection information being at the second value. The method can include receiving a source bit stream, encoding bits of the source bit stream according to the selected optimized FEC code into a series of FEC encoded bits, and a parity check matrix of the first optimized FEC code has a first average information bit node degree, and a parity check matrix of the second optimized FEC code has a second average information bit node degree.

Abstract: A multiple access scheme is described. A first bit stream is scrambled from a first terminal according to a first scrambling signature. A second bit stream is scrambled from a second terminal according to a second scrambling signature, wherein the first bit stream and the second bit stream are encoded using a low rate code. The first scrambling signature and the second scrambling signature are assigned, respectively, to the first terminal and the second terminal to provide a multiple access scheme.

Abstract: A method and apparatus allows single port memory devices to be accessed as pseudo two port memory devices. An access table is created to map the single port memory device to a single port even bank and a single port odd bank. The single port memory device is then accessed based on the mapping. An initial number of entries from the access table are retrieved in order to read addresses in the memory device until a predetermined delay expires. Simultaneous operations are then performed to read from rows in the memory device and write to rows in the memory device. Once all memory addresses have been read, write operations are sequentially performed in rows of the memory device based on the remaining entries of the access table.

Abstract: An approach for increasing transmission throughput of a non-linear wireless channel, and efficient decoding of the transmitted signal via a simplified receiver, is provided. A signal reflects a source signal, and includes linear inter-symbol interference based on a faster-than-Nyquist signaling rate and a tight frequency roll-off, and non-linear interference based on high-power amplification for transmission over the wireless channel. The signal is received over a non-linear wireless channel, and is processed via a plurality of decoding iterations. A set of soft information of a current decoding iteration is generated based on a current estimate of the source signal and a final set of soft information from a previous decoding iteration. The current estimate of the source signal is based on an estimate of the linear ISI and the non-linear interference, which is based on the final set of soft information from the previous decoding iteration.

Abstract: A method and apparatus allows single port memory devices to be accessed as pseudo two port memory devices. An access table is created to map the single port memory device to a single port even bank and a single port odd bank. The single port memory device is then accessed based on the mapping. An initial number of entries from the access table are retrieved in order to read addresses in the memory device until a predetermined delay expires. Simultaneous operations are then performed to read from rows in the memory device and write to rows in the memory device. Once all memory addresses have been read, write operations are sequentially performed in rows of the memory device based on the remaining entries of the access table.

Abstract: A satellite terminal and a machine-implemented method are provided for encoding a burst header of a burst for transmission on an inroute. One component of a group of satellite terminal components consisting of an ASIC, a FPGA, and a DSP, generates a burst header having five information bits encoded therein. The five information bits may be encoded using a Reed-Muller code, a (32, 5) block code or a convolutional code having a code rate of either 1/5 or 1/10. The five information bits may represent one or more of a modulation type for a payload of the burst, a code rate for encoding the payload, a code type, and a spreading factor for spreading the payload during transmission. A satellite gateway and a machine-implemented method are also provided for decoding a burst header of a burst received on an inroute as described above.

Abstract: Systems and methods are described for performing Layered Belief LDPC decoding on received Standard Belief LDPC encoded data bursts. In on implementation, a receiver: demodulates a signal, the demodulated signal including a noise corrupted signal derived from a codeword encoded using standard belief LDPC encoding; converts the noise corrupted signal derived from the standard belief LDPC encoded codeword to a noise corrupted signal derived from a layered belief LDPC encoded codeword; and decodes the noise corrupted signal derived from the layered belief LDPC encoded codeword using a layered belief LDPC decoder. In further implementations, systems are described for reducing collisions in Layered Belief LDPC decoders that occur when multiple parity checks need the same soft decision at the same time. In these implementations, elements in an original LBD decoder table are rearranged to increase the distance between elements specifying the same location in a RAM where soft decisions are stored.

Abstract: Methods and devices are provided. Devices asynchronously transmit, without diversity, bursts including information encoded using a low rate FEC code having a code rate no higher than ½. A terminal receives transmitted multiple overlapping bursts. The terminal detects and decodes bursts in a window of burst times, performs an iteration of an iterative interference cancellation process, and when at least one burst of at least a portion of the window remains incorrectly decoded, another iteration of the iterative cancellation process is performed as long as a maximum number of repeated iterations has not yet been performed. When all of the bursts in at least the portion of the window are correctly decoded, the window is advanced by an amount of burst time, at least the portion of the window is updated, and the iterations may be repeated. Correctly decoded bursts may be passed to a next process or device.

Abstract: A method and system for providing high throughput communications via a Radio Frequency (RF) satellite are disclosed. The method includes providing a plurality of information bit streams intended for a plurality of downlinks; modulating an uplink stream including the plurality of information bit streams with an uplink modulation scheme to generate an uplink signal; transmitting the uplink signal to the satellite; and partitioning, at the satellite, the uplink signal into a plurality of downlink signals, each one intended for one of the plurality of downlinks. In the method, the uplink stream includes the plurality of information bit streams.

Abstract: An approach for increasing transmission throughput of a non-linear wireless channel, and efficient decoding of the transmitted signal via a simplified receiver, is provided. A signal reflects a source signal, and includes linear inter-symbol interference based on a faster-than-Nyquist signaling rate and a tight frequency roll-off, and non-linear interference based on high-power amplification for transmission over the wireless channel. The signal is received over a non-linear wireless channel, and is processed via a plurality of decoding iterations. A set of soft information of a current decoding iteration is generated based on a current estimate of the source signal and a final set of soft information from a previous decoding iteration. The current estimate of the source signal is based on an estimate of the linear ISI and the non-linear interference, which is based on the final set of soft information from the previous decoding iteration.

Abstract: An approach for increasing transmission throughput of a non-linear wireless channel, and efficient decoding of the transmitted signal via a simplified receiver, is provided. A signal reflects a source signal, and includes linear inter-symbol interference based on a faster-than-Nyquist signaling rate and a tight frequency roll-off, and non-linear interference based on high-power amplification for transmission over the wireless channel. The signal is received over a non-linear wireless channel, and is processed via a plurality of decoding iterations. A set of soft information of a current decoding iteration is generated based on a current estimate of the source signal and a final set of soft information from a previous decoding iteration. The current estimate of the source signal is based on an estimate of the linear ISI and the non-linear interference, which is based on the final set of soft information from the previous decoding iteration.

Abstract: A satellite terminal and a machine-implemented method are provided for encoding a burst header of a burst for transmission on an inroute. One component of a group of satellite terminal components consisting of an ASIC, a FPGA, and a DSP, generates a burst header having five information bits encoded therein. The five information bits may be encoded using a Reed-Muller code, a (32, 5) block code or a convolutional code having a code rate of either 1/5 or 1/10. The five information bits may represent one or more of a modulation type for a payload of the burst, a code rate for encoding the payload, a code type, and a spreading factor for spreading the payload during transmission. A satellite gateway and a machine-implemented method are also provided for decoding a burst header of a burst received on an inroute as described above.

Abstract: A satellite terminal and a machine-implemented method are provided for encoding a burst header of a burst for transmission on an inroute. One component of a group of satellite terminal components consisting of an ASIC, a FPGA, and a DSP, generates a burst header having five information bits encoded therein. The five information bits may be encoded using a Reed-Muller code, a (32, 5) block code or a convolutional code having a code rate of either 1/5 or 1/10. The five information bits may represent one or more of a modulation type for a payload of the burst, a code rate for encoding the payload, a code type, and a spreading factor for spreading the payload during transmission. A satellite gateway and a machine-implemented method are also provided for decoding a burst header of a burst received on an inroute as described above.

Abstract: Methods and devices are provided. Devices asynchronously transmit, without diversity, bursts including information encoded using a low rate FEC code having a code rate no higher than ½. A terminal receives transmitted multiple overlapping bursts. The terminal detects and decodes bursts in a window of burst times, performs an iteration of an iterative interference cancellation process, and when at least one burst of at least a portion of the window remains incorrectly decoded, another iteration of the iterative cancellation process is performed as long as a maximum number of repeated iterations has not yet been performed. When all of the bursts in at least the portion of the window are correctly decoded, the window is advanced by an amount of burst time, at least the portion of the window is updated, and the iterations may be repeated. Correctly decoded bursts may be passed to a next process or device.

Abstract: An approach is provided for increasing transmission throughput rates for a source signal transmitted over a wireless channel, applying faster-than-Nyquist (FTN) signaling rates combined with tight frequency roll-off to the a source signal. A receiver is provided that compensates for ISI effects induced by the FTN rate and tight frequency roll-off, where the complexity of the receiver grows only linearly with the interference memory. The receiver comprises an equalizer configured to compensate for the ISI effects, and a decoder configured to decode the output of the equalizer to determine and regenerate the source signal. The receiver processes the received signal via a plurality of processing iterations. For one processing iteration, the decoder generates a set of a posteriori soft information based on the output of the equalizer, and the equalizer uses the a posteriori soft information as a priori soft information for a subsequent processing iteration.

Abstract: A multiple access scheme is described. A first bit stream is scrambled from a first terminal according to a first scrambling signature. A second bit stream is scrambled from a second terminal according to a second scrambling signature, wherein the first bit stream and the second bit stream are encoded using a low rate code. The first scrambling signature and the second scrambling signature are assigned, respectively, to the first terminal and the second terminal to provide a multiple access scheme.

Abstract: A signal transmission approach comprises encoding a source signal (comprising source symbols) to generate a corresponding encoded signal. The encoded signal is modulated by mapping each source symbol to a respective signal constellation point of an applied signal constellation to generate a modulated signal. The modulated signal is pre-distorted based on a distortion estimate to generate a pre-distorted signal. The pre-distorted signal is filtered to generate a filtered signal. The filtered signal is frequency translated and amplified to generate a transmission signal for transmission via an uplink channel of a satellite communications system. To increase throughput, the source signal is processed through the apparatus and the resulting transmission signal is generated at a Faster-than-Nyquist (FTN) symbol rate and with a tight frequency roll-off. The modulated signal is pre-distorted based on a distortion estimate relating to the nonlinearity and the filters applied before and/or after the pre-distorter.

Abstract: A multiple access scheme is described. A first bit stream is scrambled from a first terminal according to a first scrambling signature. A second bit stream is scrambled from a second terminal according to a second scrambling signature, wherein the first bit stream and the second bit stream are encoded using a low rate code. The first scrambling signature and the second scrambling signature are assigned, respectively, to the first terminal and the second terminal to provide a multiple access scheme.

Abstract: A multiple access scheme is described. A first bit stream is scrambled from a first terminal according to a first scrambling signature. A second bit stream is scrambled from a second terminal according to a second scrambling signature, wherein the first bit stream and the second bit stream are encoded using a low rate code. The first scrambling signature and the second scrambling signature are assigned, respectively, to the first terminal and the second terminal to provide a multiple access scheme.