Systems and methods are provided for encoding data based on an LDPC code using various inversion mechanisms to obtain parity bits. In some embodiments, an LDPC encoder may compute parity bits using a speculative recursion and correction mechanism. In these embodiments, the LDPC encoder may initiate a recursion using at least one speculative value in place of the actual value for a parity component. The speculative values may then be corrected using a correction factor. In other embodiments, an LDPC encoder is provided that can perform a blockwise inversion mechanism. This mechanism may be used on LDPC codes with parity check matrices having a parity portion composed partially of a large triangular matrix. In still other embodiments, a generic LDPC encoder is provided. The generic LDPC encoder can implement a variety of different encoding techniques, such as different inversion mechanisms, and may be processor-based or finite state machine-based.

A wireless device generates a High Efficiency (HE) Physical layer Protocol Data Units (PPDU) including a non-High Throughput Signal (L-SIG) field and transmits the HE PPDU. Transmitting the HE PDDU includes transmitting a set of extra tones with the L-SIG field. The set of extra tones include a sequence of values, and first, second, third, and fourth values of the sequence of values respectively correspond to BPSK constellation values of 1, 1, 1, and +1. The set of extra tones may include 28th, 27th, 27th, and 28th subcarriers, relative to a center (zero) subcarrier, of a 20 MHz bandwidth of the HE PPDU, and may be used to transmit the first, second, third, and fourth values of the sequence of values, respectively. Another wireless device may receive the HE PPDU, and may use the set of extra tones to estimate a channel.

In a transmission device, a determining unit determines, for use in transmission, an LDPC encoding method corresponding to occurrence conditions of external noise from a plurality of LDPC encoding methods each having the same code length and the same code rate and being defined by a different parity check matrix, and an encoding unit generates a codeword bit sequence by encoding transmission data using the LDPC encoding method determined by the determining unit.

A decoding algorithm with an enhanced parity check matrix and a re-encoding scheme for LDPC codes is disclosed. The decoding algorithm includes the steps of: providing the enhanced parity check matrix; receiving a message part of an original codeword encoded by a generator matrix from the enhanced parity check matrix; setting a LLR for each bit node of the enhanced parity check matrix; processing hard decision on the message part of the original codeword; encoding the message part of the original codeword by the generator matrix to generate a new codeword having a generated parity part; comparing the original parity part with the generated parity part to find out bits of difference; voting candidate error bits to choose the most probably erratic bits; modifying LLR of the chosen bits to have a modified codeword; and processing a conventional iterative decoding procedure on the modified codeword to have a processed codeword.

A method and apparatus for transmitting an uplink signal in a wireless communication system are discussed. The method includes multiplexing control information in all layers with a plurality of data blocks of the uplink signal; and transmitting the uplink signal to a base station, wherein the number of modulation symbols per layer for the control information is determined using a reciprocal of a sum of spectral efficiencies for respective data blocks of the plurality of data blocks, and a spectral efficiency for a data block is obtained based on a ratio of a size of the data block to the number of resource elements (REs) for an initial physical uplink shared channel (PUSCH) transmission of the data block.

A wireless device generates a High Efficiency (HE) Physical layer Protocol Data Units (PPDU) including a non-High Throughput Signal (L-SIG) field and transmits the HE PPDU. Transmitting the HE PDDU includes transmitting a set of extra tones with the L-SIG field. The set of extra tones include a sequence of values, and first, second, third, and fourth values of the sequence of values respectively correspond to BPSK constellation values of 1, 1, 1, and +1. The set of extra tones may include 28th, 27th, 27th, and 28th subcarriers, relative to a center (zero) subcarrier, of a 20 MHz bandwidth of the HE PPDU, and may be used to transmit the first, second, third, and fourth values of the sequence of values, respectively. Another wireless device may receive the HE PPDU, and may use the set of extra tones to estimate a channel.

A wireless device generates a High Efficiency (HE) Physical layer Protocol Data Units (PPDU) including a non-High Throughput Signal (L-SIG) field and transmits the HE PPDU. Transmitting the HE PDDU includes transmitting a set of extra tones with the L-SIG field. The set of extra tones include a sequence of values, and first, second, third, and fourth values of the sequence of values respectively correspond to BPSK constellation values of 1, 1, 1, and +1. The set of extra tones may include 28th, 27th, 27th, and 28th subcarriers, relative to a center (zero) subcarrier, of a 20 MHz bandwidth of the HE PPDU, and may be used to transmit the first, second, third, and fourth values of the sequence of values, respectively. Another wireless device may receive the HE PPDU, and may use the set of extra tones to estimate a channel.

Systems and methods are provided for encoding data based on an LDPC code using various inversion mechanisms to obtain parity bits. In some embodiments, an LDPC encoder may compute parity bits using a speculative recursion and correction mechanism. In these embodiments, the LDPC encoder may initiate a recursion using at least one speculative value in place of the actual value for a parity component. The speculative values may then be corrected using a correction factor. In other embodiments, an LDPC encoder is provided that can perform a blockwise inversion mechanism. This mechanism may be used on LDPC codes with parity check matrices having a parity portion composed partially of a large triangular matrix. In still other embodiments, a generic LDPC encoder is provided. The generic LDPC encoder can implement a variety of different encoding techniques, such as different inversion mechanisms, and may be processor-based or finite state machine-based.

A method for transmitting an uplink signal by a communication apparatus in a wireless communication system is discussed. The method includes multiplexing control information with at least one of a plurality of data blocks to generate a bit sequence; and transmitting the uplink signal including the bit sequence. When the control information includes a first type of control data, the control information is multiplexed with all of the plurality of data blocks. When the control information includes a second type of control data, the control information is multiplexed only with a specific data block among the plurality of data blocks. The first type of control data includes acknowledgement/negative acknowledgement (ACK/NACK) information, and the second type of control data includes channel quality information.

A decoding algorithm with an enhanced parity check matrix and a re-encoding scheme for LDPC codes is disclosed. The decoding algorithm includes the steps of: providing the enhanced parity check matrix; receiving a message part of an original codeword encoded by a generator matrix from the enhanced parity check matrix; setting a LLR for each bit node of the enhanced parity check matrix; processing hard decision on the message part of the original codeword; encoding the message part of the original codeword by the generator matrix to generate a new codeword having a generated parity part; comparing the original parity part with the generated parity part to find out bits of difference; voting candidate error bits to choose the most probably erratic bits; modifying LLR of the chosen bits to have a modified codeword; and processing a conventional iterative decoding procedure on the modified codeword to have a processed codeword.