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 physical layer (PL) frame generation method is provided. A PL payload is generated by encoding and modulating source data based on a first modcod of a first set. A synchronization header (a unique word (UW) of a UW set) is appended to the PL payload. The UWs of the set respectively correspond to different modcods of the first set, and the UW corresponds to the first modcod. A PL header is appended to the synchronization header and PL payload to form the PL frame. The PL header comprises a second UW and physical layer signaling (PLS). The PLS comprises encoded data fields reflecting a length of the PL frame, where the data fields are encoded based on a second modcod scheme of a second set. The first modcod set is designed for an SNR operating range relatively lower than the SNR operating range of the second modcod set.

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.

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: 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 decoding a low density parity check (LDPC) coded signal. Edge values associated with a structured parity check matrix used to generate the LDPC coded signal are retrieved from memory. The edge values specify the relationship of bit nodes and check nodes, and are stored within memory according to a predetermined scheme that permits concurrent retrieval of a set of the edge values. A decoded signal corresponding to the LDPC coded signal is output based on the retrieved edge values.

Abstract: A parameterized interleaver design process is provided, which optimizes the design for interleavers of any size, and can be completely specified using only a few design parameters. According to the parameterized interleaver design process an interleaver ?(i) of a length N is generated. A number of subpermutation masks are defined, and a first intermediate interleaver permutation is partitioned into a number of subgroups, wherein the number of subgroups corresponds with the number of subpermutation masks. Each of the subgroups of the first intermediate interleaver permutation is partitioned into a number of further subgroups, and each of the subpermutation masks is applied to each of the further subgroups of a corresponding subgroup of the first intermediate interleaver permutation, resulting in a corresponding portion of a second intermediate interleaver permutation. The resulting interleaver ?(i) is generated based at least in part on the first and second intermediate interleaver permutations.

Abstract: A parameterized interleaver design process is provided, which optimizes the design for interleavers of any size, and can be completely specified using only a few design parameters. According to the parameterized interleaver design process an interleaver ?(i) of a length N is generated. A number of subpermutation masks are defined, and a first intermediate interleaver permutation is partitioned into a number of subgroups, wherein the number of subgroups corresponds with the number of subpermutation masks. Each of the subgroups of the first intermediate interleaver permutation is partitioned into a number of further subgroups, and each of the subpermutation masks is applied to each of the further subgroups of a corresponding subgroup of the first intermediate interleaver permutation, resulting in a corresponding portion of a second intermediate interleaver permutation. The resulting interleaver ?(i) is generated based at least in part on the first and second intermediate interleaver permutations.