Communication transmitter for retransmitting medium access control (MAC) protocol data unit (MPDU)

A communication transmitter for retransmitting a medium access control (MAC) protocol data unit (MPDU) to a communication receiver over a communication channel using a hybrid automatic repeat request (HARQ) retransmission scheme, the MPDU comprising a plurality of information bits, the communication transmitter comprising:

• a processor configured to:
• determine the MPDU to be retransmitted based on a block acknowledgement (Block ACK) frame received from the communication receiver, the Block ACK frame indicating previously correctly decoded MPDUs at the communication receiver, and to generate a bit sequence to be transmitted to the communication receiver, wherein the bit sequence comprises the plurality of information bits;
• select a first group of information bits and a second group of information bits from the plurality of information bits of the MPDU, to encode the first group of information bits using a forward error correction (FEC) encoder to obtain a first group of parity bits, to encode the second group of information bits using the FEC encoder to obtain a second group of parity bits, and to include the first group of parity bits and the second group of parity bits into the bit sequence;
• select a first plurality of subgroups of information bits from the first group of information bits and a first plurality of subgroups of parity bits from the first group of parity bits, and to select a second plurality of subgroups of information bits from the second group of information bits and a second plurality of subgroups of parity bits from the second group of parity bits;
• and
• a communication interface configured to transmit the bit sequence to the communication receiver for retransmitting the MPDU to the communication receiver.

A communication receiver for receiving a retransmitted medium access control (MAC) protocol data unit (MPDU) from a communication transmitter over a communication channel using a hybrid automatic repeat request (HARQ) retransmission scheme, the retransmitted MPDU comprising a plurality of information bits, the retransmitted MPDU being associated with a previously received MPDU, the communication receiver comprising:

• a communication interface configured to transmit a block acknowledgement (Block ACK) frame to the communication transmitter, the Block ACK frame indicating previously correctly decoded MPDUs at the communication receiver, and to receive a bit sequence from the communication transmitter, wherein the bit sequence comprises the plurality of information bits;
• and
• a processor configured to:
• determine a plurality of log-likelihood ratios (LLRs) associated with the plurality of information bits, and to combine the determined plurality of LLRs with a previously determined plurality of LLRs associated with the previously received MPDU, wherein the bit sequence further comprises a plurality of parity bits;
• and
• determine a further plurality of LLRs associated with the plurality of parity bits, and to include a subgroup of the determined further plurality of LLRs associated with the plurality of parity bits in the bit sequence.

A method of operating a communication receiver for receiving a retransmitted medium access control (MAC) protocol data unit (MPDU) from a communication transmitter over a communication channel using a hybrid automatic repeat request (HARQ) retransmission scheme, the retransmitted MPDU comprising a plurality of information bits, the retransmitted MPDU being associated with a previously received MPDU, the communication receiver comprising a communication interface and a processor, the method comprising:

• transmitting, by the communication interface, a block acknowledgement (Block ACK) frame to the communication transmitter, the Block ACK frame indicating previously correctly decoded MPDUs at the communication receiver;
• receiving, by the communication interface, a bit sequence from the communication transmitter, wherein the bit sequence comprises the plurality of information bits;
• determining, by the processor, a plurality of log-likelihood ratios (LLRs) associated with the plurality of information bits, wherein the bit sequence further comprises a plurality of parity bits;
• combining, by the processor, the determined plurality of LLRs with a previously determined plurality of LLRs associated with the previously received MPDU;
• determining, by the processor, a further plurality of LLRs associated with the plurality of parity bits;
• and
• using, by the processor, a subgroup of the determined further plurality of LLRs associated with the plurality of parity bits to include in the bit sequence.