Abstract: A method and apparatus for Turbo encoding uses a set of rate-compatible Turbo Codes optimized at high code rates and derived from a universal constituent code. The Turbo Codes have rate-compatible puncturing patterns. The method comprises: encoding a signal at a first and second encoder using a best rate ½ constituent code universal with higher code rates, the first encoder and the second encoder each producing a respective plurality of parity bits for each information bit; puncturing the respective plurality of parity bits at each encoder with a higher rate best puncturing patterns; and puncturing the respective plurality of parity bits at each encoder with a lower rate best puncturing pattern. In a variation, the best rate ½ constituent code represents a concatenated of polynomials 1+D2+D3 (octal 13) and 1+D+D3 (octal 15), D a data bit. A Turbo Encoder is provided which has hardware to implement the method.

Abstract: A system and method for data transmissions in a wireless communications system, which accommodates for a periodic blockage of the transmission signal, is provided. A data stream is segmented into packets of a predetermined fixed-size for a burst-mode transmission over a channel of the communications system, wherein the transmission is subject to a periodic blockage. A forward error correction outer code is then applied to the packets of the data stream for recovery of packets subjected to the periodic blockage, and a unique word is added to each packet for acquisition of frequency, carrier phase and symbol timing of the respective packet. The packets of the data stream are interleaved based on an interleaver of a depth based at least in part on a ratio of a blockage free duration between two consecutive blockages of the periodic blockage to a duration of each blockage of the periodic blockage.

Abstract: A signal transmission approach comprises encoding a source signal (comprising a plurality of 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.

Abstract: The present invention provides a low density parity check (LDPC) code system and method of using such a system. A transmitted LDPC code block size may be chosen such that the minimum transmitted block size is minimized. Further, the system provides for intermediate LDPC code block size support. Finally, a common decoder architecture may be used to decode different LDPC code rates and block sizes.

Abstract: An approach is provided for an improved coding approach for efficient header signaling in broadband communications networks, to provide support of expanded modulation and coding scheme sets that facilitate an expansion of the operational ranges of user terminals within such networks and finer granularity within such operational ranges. A mode indicator field of a frame header identifies a modulation/coding mode applied to a data payload of the data frame. The modulation/coding mode is one of either a first or second set of modulation/coding modes. The mode indicator field is encoded and modulated. When the modulation/coding mode is one of the first set, the modulation of the encoded mode indicator field is applied in a first mode, and when the modulation/coding mode is one of the second set, the modulation of the encoded mode indicator field is applied in a second mode.

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 new coded continuous phase modulation (CPM) scheme is proposed to enhance physical layer performance of the current DVB-RCS standard for a satellite communication system. The proposed CPM scheme uses a phase pulse design and combination of modulation parameters to shape the power spectrum of CPM signal in order to improve resilience to adjacent channel interference (ACI). Additionally, it uses a low complexity binary convolutional codes and S-random bit interleaving. Phase response using the proposed CPM scheme is a weighted average of the conventional rectangular and raised-cosine responses and provides optimum response to minimize frame error rate for a given data rate.

Abstract: An approach is provided for an improved coding approach for efficient header signaling in broadband communications networks, to provide support of expanded modulation and coding scheme sets that facilitate an expansion of the operational ranges of user terminals within such networks and finer granularity within such operational ranges. A mode indicator field of a frame header identifies a modulation/coding mode applied to a data payload of the data frame. The modulation/coding mode is one of either a first or second set of modulation/coding modes. The mode indicator field is encoded and modulated. When the modulation/coding mode is one of the first set, the modulation of the encoded mode indicator field is applied in a first mode, and when the modulation/coding mode is one of the second set, the modulation of the encoded mode indicator field is applied in a second mode.

Abstract: Modulation and coding schemes are provided for improved performance of wireless communications systems to support services and applications for terminals with operational requirements at relatively low Es/N0 ratios and terminals at relatively high Es/N0 ratios. The new modulation and coding schemes provide new BCH codes, low density parity check (LDPC) codes and interleaving methods. The modulation and coding schemes also provide new modulation signal constellations.

Abstract: Approaches are provided for closing communications channel links (e.g., for small terminal applications in satellite communications systems), at lower effective data rates, in a most power efficient manner, while still meeting regulatory requirements. Such approaches employ modulation and coding schemes that facilitate such lower effective data rates in a most power efficient manner. The new modulation and coding schemes include new low density parity check (LDPC) codes.

Abstract: Modulation and coding schemes are provided for improved performance of wireless communications systems to support services and applications for terminals with operational requirements at relatively low Es/N0 ratios and terminals at relatively high Es/N0 ratios. The new modulation and coding schemes provide new BCH codes, low density parity check (LDPC) codes and interleaving methods. The modulation and coding schemes also provide new modulation signal constellations.

Abstract: Modulation and coding schemes are provided for improved performance of wireless communications systems to support services and applications for terminals with operational requirements at relatively low ES/N0 ratios. The provided modulation and coding schemes will support current and future communications services and applications for terminals with operational requirements at relatively low ES/N0 ratios, and will provide modulation and coding schemes that offer finer granularity within an intermediate operational range of ES/N0 ratios. The new modulation and coding schemes provide new BCH codes, and low density parity check (LDPC) codes.

Abstract: Modulation and coding schemes are provided for improved performance of wireless communications systems to support services and applications for terminals with operational requirements at relatively low Es/N0 ratios. The new modulation and coding schemes provide new BCH codes, low density parity check (LDPC) codes and interleaving methods.

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: An approach is provided for encoding a source signal based on a structured parity check matrix of a Low Density Parity Check (LDPC) code. The LDPC code is represented by stored information reflecting a tabular format of rows and columns, wherein each row represents occurrences of one values within a respective column of the parity check matrix, and wherein the columns of the parity check matrix are derived according to an operation based on the respective rows of the stored information. Blocks of information bits of the source signal are encoded based on the LDPC code to generate an encoded signal. Row indices of 1's in a column index of the parity check matrix are given at a respective row according to the stored information. The LDPC code is of a structure that facilitates use of a plurality of parallel engines for decoding the encoded signal.

Abstract: An approach is provided for distributing multi-media information from a satellite broadcast system. A hub receives a signal from the satellite broadcast system, wherein the signal represents video information and audio information associated with multiple broadcast channels. The hub centrally demodulates and decodes the received signal for distribution to one of a number of access point devices. According to one embodiment of the present invention, the decoded signal represents uncompressed video and audio information corresponding to one of the broadcast channels. The access point devices convert the received decoded signal for output respective displays (e.g., television sets). The hub can also be equipped with an interface to provide access to a public data network, such as the global Internet. Further, the hub can be supplied with a digital video recording capability.

Abstract: Method and apparatus for implementing LDPC codes in an IEEE 802.11 standard system configured to operate in a Multiple-Input, Multiple-Output (MIMO) schema. A method in accordance with the present invention comprises defining a base LDPC code, having a length equal to an integer number of data carriers in an ODFM symbol, transmitting the base LDPC code over a plurality of sub-carriers, wherein the base code is transmitted at an expected phase on sub-carriers specified by the IEEE 802.11 standard system, and transmitting the base LDPC code on other sub-carriers than those specified by the IEEE 802.11 standard system, wherein the base LDPC code on the other sub-carriers is transmit offset in phase from the base LDPC code on the specified sub-carriers.

Abstract: An approach is provided for encoding a source signal based on a structured parity check matrix of a Low Density Parity Check (LDPC) code. The LDPC code is represented by stored information reflecting a tabular format of rows and columns, wherein each row represents occurrences of one values within a respective column of the parity check matrix, and wherein the columns of the parity check matrix are derived according to an operation based on the respective rows of the stored information. Blocks of information bits of the source signal are encoded based on the LDPC code to generate an encoded signal. Row indices of 1's in a column index of the parity check matrix are given at a respective row according to the stored information. The LDPC code is of a structure that facilitates use of a plurality of parallel engines for decoding the encoded signal.

Abstract: A multiple access scheme is described. One or more encoders are configured to encode a plurality of bit streams using Low Density Parity Check (LDPC) coding. The bit streams correspond to a respective plurality of terminals. The plurality of bit streams are converted to provide a multiple access scheme for the terminals.

Abstract: Methods, systems and software are provided for high order signal modulation based on improved signal constellation and bit labeling designs for enhanced performance characteristics, including decreased power consumption. According to the improved signal constellation and bit labeling designs for enhanced performance characteristics, designs for 8-ary, 16-ary, 32-ary and 64-ary signal constellations are provided. According to an 8-ary constellation, improved bit labeling and bit coordinates are provided for a 1+7APSK signal constellation. According to a 16-ary constellation, improved bit labeling and bit coordinates are provided for a 6+10APSK signal constellation. According to three 32-ary constellations, improved bit labeling and bit coordinates are provided for a 16+16APSK signal constellation and two 4+12+16APSK signal constellations.