Abstract: A communication device (or device) includes a communication interface and processor that support communications with one or more other devices within a communication system. The processor generates and interprets different signals, frames, packets, symbols, etc. for transmission to other devices and that have been received from other devices. The device generates modulation symbols based on two-dimensional (2-D) symbol locations of a constellation. The device generates the 2-D symbol locations using based on recursive one-dimensional (1-D) Gray code formula applied to bits of symbol values. The recursive 1-D Gray code formula specifies first symbol locations for symbol values having a first number of bits (e.g., n) based on second symbol locations for other symbol values having one fewer bits per symbol (e.g., n?1). The device maps data symbols to the 2-D symbol locations to generate the modulation symbols and transmits the modulation symbols to another communication device.

Abstract: Impulse and/or burst noise signal to noise ratio (SNR) aware concatenated forward error correction (FEC). Adaptive processing is performed on a signal based on one or more effects which may deleteriously modify a signal. For example, based on a modification of a signal to noise ratio (SNR) associated with one or more impulse or burst noise events, which may be estimated, different respective processing may be performed selectively to differently affected bits associated with the signal. For example, two respective SNRs may be employed: a first SNR for one or more first bits, and a second SNR for one or more second bits. For example, as an impulse or burst noise event may affect different respective bits of a codeword differently, and adaptive processing may be made such that different respective bits of the codeword may be handled differently.

Abstract: A communication device operates to support communications with one or more other communication devices. The communication device includes a processor and a communication interface to perform various operations including receiving forward error correction (FEC) coded signals from another communication device. The communication device iteratively decodes the FEC coded signals to make estimates of information encoded therein. The communication device then determines an operational error check rate based on error check failure of at least one of the FEC coded signals after performing a predetermined number of decoding iterations (e.g., that is less than a maximum number of decoding iterations performed by the device). The device then determines a signal to noise ratio (SNR) margin of the communication device by applying the operational error check rate to a characterization of the communication device that relates error check rate and SNR.

Abstract: A communication device includes a communication interface and a processor. In one example, the processor generates an orthogonal frequency division multiplexing (OFDM) symbol that includes information modulated within sub-carriers and then interleaves the sub-carriers of the OFDM symbol to generate an interleaved OFDM symbol. This interleaving of the sub-carriers operates to write the plurality of sub-carriers to rows of a two dimensional (2D) array and read the plurality of sub-carriers from columns of the 2D array. This interleaving also operates to read a column of the columns using a bit-reversed address of the column when the bit-reversed address is less than a number of the columns and using the address of the column when the bit-reversed address is greater than or equal to the number of the columns. The processor transmits, via the communication interface, the interleaved OFDM symbol to another communication device.

Abstract: A wireless local area network (WLAN) transmitter includes a baseband processing module and a plurality of radio frequency (RF) transmitters. The processing module selects one of a plurality of modes of operation based on a mode selection signal. The processing module determines a number of transmit streams based on the mode selection signal. The processing of the data further continues by converting encoded data into streams of symbols in accordance with the number of transmit streams and the mode selection signal. A number of the plurality of RF transmitters are enabled based on the mode selection signal to convert a corresponding one of the streams of symbols into a corresponding RF signal such that a corresponding number of RF signals is produced.

Abstract: Selective merge and partial reuse LDPC (Low Density Parity Check) code construction for limited number of layers Belief Propagation (BP) decoding. Multiple LDPC matrices may be generated from a base code, such that multiple/distinct LDPC coded signals may be encoded and/or decoded within a singular communication device. Generally speaking, a first LDPC matrix is modified in accordance with one or more operations thereby generating a second LDPC matrix, and the second LDPC matrix is employed in accordance with encoding an information bit thereby generating an LDPC coded signal (alternatively performed using an LDPC generator matrix corresponding to the LDPC matrix) and/or decoding processing of an LDPC coded signal thereby generating an estimate of an information bit encoded therein. The operations performed on the first LDPC matrix may be any one of, or combination of, selectively merging, deleting, partially re-using one or more sub-matrix rows, and/or partitioning sub-matrix rows.

Abstract: Optimal period rate matching for turbo coding. A means is provided herein by which a nearly optimal (e.g., optimal for one block size and sub-optimal for others) periodic puncturing pattern that depends on a mother code. Any desired rate matching can be achieved using the means and approaches presented herein to ensure an appropriate rate of an encoded block output from a turbo encoder so that the subsequently modulated signal generated there from has the appropriate rate. In addition, some embodiments can also employ shifting for another design level available in accordance with puncturing employed to provide for periodic rate matching. Selectivity can also be employed, such that, a first periodic puncturing pattern can be applied at a first time to ensure a first rate, and a second periodic puncturing pattern can be applied at a second time to ensure a second rate.

Abstract: A communication device is configured to communicate coded information to other communication device(s). The communication device uses NCPs to indicate locations of codewords within signal(s) transmitted to the other communication device(s). The communication device is configured to encode NCP(s) using an FEC code to generate coded NCP(s) and also to encode the NCP(s) using a cyclic redundancy check (CRC) code to generate NCP CRC bits. The communication device is also configured to encode the NCP CRC bits using the FEC code to generate coded NCP CRC bits. The communication device is then configured to generate OFDM or OFDMA symbol(s) include the coded NCP(s) and the coded NCP CRC bits to indicate beginnings of codeword(s) within at least one of the OFDM symbol(s) and/or additional OFDM symbol(s). The communication device is also configured to transmit the OFDM or OFDMA symbols to another communication device via a communication interface of the communication device.

Abstract: A communication device (device) includes a processor configured to generate an initial ranging LDPC coded signal based on a first LDPC code and then transmits the initial ranging LDPC coded signal to another device (e.g., via a communication interface) for use by the other device for coarse power and timing adjustment. Then, the processor processes a received transmit opportunity signal to identify a transmit opportunity time period. The processor then generates a fine ranging LDPC coded signal based on a second LDPC code and transmits the fine ranging LDPC coded signal to the other device during the transit opportunity time period for use by the other device for fine power and timing adjustment. In some instances, the processor may be configured to generate one or more wideband probe signals for transmission to the other device in conjunction with or instead of the fine ranging LDPC coded signals.

Abstract: Optimal period rate matching for turbo coding. A means is provided herein by which a nearly optimal (e.g., optimal for one block size and sub-optimal for others) periodic puncturing pattern that depends on a mother code. Any desired rate matching can be achieved using the means and approaches presented herein to ensure an appropriate rate of an encoded block output from a turbo encoder so that the subsequently modulated signal generated there from has the appropriate rate. In addition, some embodiments can also employ shifting for another design level available in accordance with puncturing employed to provide for periodic rate matching. Selectivity can also be employed, such that, a first periodic puncturing pattern can be applied at a first time to ensure a first rate, and a second periodic puncturing pattern can be applied at a second time to ensure a second rate.

Abstract: Rate control adaptable communications. A common trellis is employed at both ends of a communication system (in an encoder and decoder) to code and decode data at different rates. The encoding employs a single encoder whose output bits may be selectively punctured to support multiple modulations (constellations and mappings) according to a rate control sequence. A single decoder is operable to decode each of the various rates at which the data is encoded by the encoder. The rate control sequence may include a number of rate controls arranged in a period that is repeated during encoding and decoding. Either one or both of the encoder and decoder may adaptively select a new rate control sequence based on a variety of operational parameters including operating conditions of the communication system, a change in signal to noise ratio (SNR), etc.

Abstract: Data puncturing ensuring orthogonality within communication systems. Puncturing is employed within communication systems to ensure orthogonality (or substantial orthogonality) of various transmissions between communication devices within communication systems. Any of a variety of types of signals can be employed herein including uncoded signals, turbo encoded signals, turbo trellis coded modulation (TTCM) encoded signals, LDPC (Low Density Parity Check) encoded signals, and RS (Reed-Solomon) encoded signals, among just some types of signals. A first transmission can be made from a first communication device to a second communication device, and the second communication device can sometimes request a subsequent transmission (e.g., a re-transmission) from the first communication device to the second communication device. Oftentimes, different information is sent from the first communication device to the second communication device within the subsequent transmission.

Abstract: Forward error correction (FEC) m-bit symbol modulation. Any desired FEC, error correction code (ECC), and/or combination thereof generates coded bits for combination with either uncoded bits, separately generated coded bits, and/or combination thereof to generate a number of symbols that undergo mapping to a constellation whose respective constellation points have a mapping characterized by a maximum minimum intra-Euclidean distance between the respective constellation points thereby generating a sequence of discrete-valued modulation symbols. The sequence of discrete-valued modulation symbols may then undergo modulation of any of a number of different operations (e.g., digital to analog conversion [e.g., digital to analog converter (DAC)], scaling, frequency shifting, filtering, etc.) to generate a continuous time signal for transmission via a communication channel. Such a device operative to perform including such functionality, circuitry, capability, etc.

Abstract: Communication device architecture for in-place constructed LDPC (Low Density Parity Check) code. Intelligent design of LDPC codes having similar characteristics there between allows for a very efficient hardware implementation of a communication device that is operative to perform encoding of respective information bit groups using more than one type of LDPC codes. A switching module can select any one of the LDPC codes within an in-place LDPC code for use by an LDPC encoder circuitry to generate an LDPC coded signal. Depending on which sub-matrices of a superimposed LDPC matrix are enabled or disabled, one of the LDPC matrices from within an in-place LDPC code matrix set may be selected. A corresponding, respective generator matrix may be generated from each respective LDPC matrix. Selection among the various LDPC codes may be in accordance with a predetermined sequence, of based operating conditions of the communication device or communication system.

Abstract: A communication device is configured to encode and/or decode low density parity check (LDPC) coded signals. Such LDPC coded signals are characterized by LDPC matrices having a particular form. An LDPC matrix may be partitioned into a left hand side matrix and the right hand side matrix. The right hand side matrix can be lower triangular such that all of the sub-matrices therein are all-zero-valued sub-matrices (e.g., all of the elements within an all-zero-valued sub-matrix have the value of “0”) except for those sub-matrices located on a main diagonal of the right hand side matrix and another diagonal that is adjacently located to the left of the main diagonal. A device may be configured to employ different LDPC codes having different LDPC matrices for different LDPC coded signals. The different LDPC matrices may be based generally on a common form (e.g., with a right hand side matrix as described above).

Abstract: A communication device is configured to encode and/or decode low density parity check (LDPC) coded signals. Such LDPC coded signals are characterized by LDPC matrices having a particular form. An LDPC matrix may be partitioned into a left hand side matrix and the right hand side matrix. The right hand side matrix can be lower triangular such that all of the sub-matrices therein are all-zero-valued sub-matrices (e.g., all of the elements within an all-zero-valued sub-matrix have the value of “0”) except for those sub-matrices located on a main diagonal of the right hand side matrix and another diagonal that is adjacently located to the left of the main diagonal. A device may be configured to employ different LDPC codes having different LDPC matrices for different LDPC coded signals. The different LDPC matrices may be based generally on a common form (e.g., with a right hand side matrix as described above).

Abstract: A communication device is configured to perform processing of one or more bits to generate a modulation symbol sequence based on one or more profiles that specify variable bit loading of bits per symbol over at least some of the modulation symbols of the modulation symbol sequence. The communication device is also configured to perform interleaving of the modulation symbol sequence to generate OFDM symbol(s). Some modulation symbols within the modulation symbol sequence that are separated by an interleaver depth may be transmitted via adjacently located sub-carriers, while other modulation symbols within the modulation sequence that are separated by more than the interleaver depth may also be transmitted via adjacently located sub-carriers. A communication device may be configured to adapt and switch between different operational parameters used for bit loading, interleaving and/or deinterleaving at different times based on any desired considerations.

Abstract: A communication device is configured to perform interleaving of a modulation symbol sequence to generate an OFDM symbol. Some modulation symbols within the modulation symbol sequence that are separated by an interleaver depth may be transmitted via adjacently located sub-carriers, while other modulation symbols within the modulation sequence that are separated by more than the interleaver depth may also be transmitted via adjacently located sub-carriers. First adjacently located sub-carriers transmit first and second modulation symbols that are separated by the interleaver depth within the modulation sequence while second adjacently located sub-carriers transmit third and fourth modulation symbol that are separated by more than the interleaver depth within the modulation sequence. A communication device may be configured to adapt and switch between different operational parameters used for interleaving and/or deinterleaving at different times based on any desired considerations.

Abstract: A communication device is configured adaptively to process a receive signal based on noise that may have adversely affected the signal during transition via communication channel. The device may be configured to identify those portions of the signal of the signal that are noise-affected (e.g., noise-affected sub-carriers of an orthogonal frequency division multiplexing (OFDM) signal), or the device may receive information that identifies those portions of the signal that are noise-affected from one or more other devices. The device may be configured to perform the modulation processing of the received signal to generate log-likelihood ratios (LLRs) for use in decoding the signal. Those LLRs associated with noise-affected portions of the signal are handled differently than LLRs associated with portions of the signal that are not noise-affected. The LLRs may be scaled based on signal to noise ratio(s) (SNR(s)) associated with the signal (e.g., based on background noise, burst noise, etc.).

Abstract: Variable modulation within combined LDPC (Low Density Parity Check) coding and modulation coding systems. Variable modulation encoding of LDPC coded symbols is presented. In addition, LDPC encoding, that generates an LDPC variable code rate signal, may also be performed as well. The encoding can generate an LDPC variable code rate and/or modulation signal whose code rate and/or modulation may vary as frequently as on a symbol by symbol basis. Some embodiments employ a common constellation shape for all of the symbols of the signal sequence, yet individual symbols may be mapped according different mappings of the commonly shaped constellation; such an embodiment may be viewed as generating a LDPC variable mapped signal. In general, any one or more of the code rate, constellation shape, or mapping of the individual symbols of a signal sequence may vary as frequently as on a symbol by symbol basis.