HARQ and link adaptation in wireless communication system
An electronic device receives a first data unit including a first hybrid automatic repeat request (HARQ) unit and transmits a second data unit including first HARQ-related information indicating that the first HARQ unit fails to be decoded. The electronic device receives a third data unit including a preamble. The preamble includes a first STF, a first LTF, a signal field, a second STF, and a second LTF, and the third data unit includes second HARQ-related information indicating whether the third data unit includes retransmitted data. The electronic device obtains a second HARQ unit based on determination that the second HARQ-related information indicates that the third data unit includes retransmitted data and decodes the second HARQ unit with the first HARQ unit.
1 . An electronic device for facilitating wireless communication, the device comprising:
one or more memories; and
one or more processors coupled to the one or more memories, the one or more processors configured to cause:
receiving a first data unit including a first short training field (STF), a first long training field (LTF), a signal field, a second STF, a second LTF, and a data field including a first hybrid automatic repeat request (HARQ) unit;
transmitting a second data unit including first HARQ-related information indicating that the first HARQ unit fails to be decoded;
receiving a third data unit including a preamble, wherein the preamble includes a first STF, a first LTF, a signal field, a second STF, and a second LTF, and the third data unit includes second HARQ-related information indicating whether the third data unit includes retransmitted data, wherein the second HARQ-related information is included in the signal field of the preamble of the third data unit, and the signal field includes a user field including a first subfield indicating a station identifier and a second subfield indicating the third data unit includes retransmitted data;
obtaining a second HARQ unit based on determination that the second HARQ-related information indicates that the third data unit includes retransmitted data; and
decoding the second HARQ unit with the first HARQ unit.
2 . The electronic device of claim 1 , wherein:
the first data unit includes a MAC header including a link adaptation control subfield including a first MCS (modulation and coding scheme) request (MRQ) subfield and a first MRQ sequence identifier (MSI) subfield,
the third data unit includes a MAC header including a link adaptation control subfield including a second MRQ subfield and a second MSI subfield,
the second MSI subfield set equal to a MSI value indicated by the first MSI subfield indicates that the third data unit includes retransmitted data, and
the second MSI subfield set different from a MSI value indicated by the first MSI subfield indicates that the third data unit does not include retransmitted data.
3 . The electronic device of claim 1 , wherein the second HARQ-related information is indicated by a bitmap including a plurality of bits, each of the plurality associated with a respective one of HARQ units in the first data unit.
4 . The electronic device of claim 1 , wherein the second HARQ-related information is indicated by a field set equal to a state of a plurality of states in a lookup table, wherein the plurality of states in the lookup table represents a respective one of error combinations of HARQ units in the first data unit.
5 . The electronic device of claim 1 , wherein a scrambler seed used for the second HARQ unit is the same as a scrambler seed used for the first HARQ unit.
6 . The electronic device of claim 1 , wherein obtaining the second HARQ unit comprises:
receiving a fourth data unit following the third data unit, the fourth data unit including a first short training field (STF), a first long training field (LTF), a signal field, a second STF, and a second LTF, and a data field; and
obtaining the second HARQ unit from the data field of the fourth data unit according to parameters in the signal field in the fourth data unit.
7 . The electronic device of claim 1 , wherein the signal field of the third data unit includes no parameter used for obtaining the second HARQ unit and the second HARQ unit is obtained according to one or more parameters in the signal field in the first data unit.
8 . The electronic device of claim 1 , wherein the first HARQ unit is a low-density parity check (LDPC) codeword including information bits and parity bits.
9 . The electronic device of claim 8 , wherein the second HARQ unit is a low-density parity check (LDPC) codeword including information bits and parity bits.
10 . The electronic device of claim 8 , wherein the second HARQ unit is a low-density parity check (LDPC) codeword including parity bits and excluding information bits.
11 . The electronic device of claim 1 , wherein the first HARQ unit is a group of low-density parity check (LDPC) codewords.
12 . The electronic device of claim 1 , wherein the first HARQ unit is a MPDU.
13 . The electronic device of claim 1 , wherein the one or more processors configured to further cause:
discarding the first HARQ unit if the third data unit include a HARQ unit that is not indicated by the first HARQ-related information.
14 . An electronic device for facilitating wireless communication, the device comprising:
one or more memories; and
one or more processors coupled to the one or more memories, the one or more processors configured to cause:
transmitting a first data unit including a first short training field (STF), a first long training field (LTF), a signal field, a second STF, a second LTF, and a data field including a first hybrid automatic repeat request (HARQ) unit;
receiving a second data unit including first HARQ-related information indicating that the first HARQ unit fails to be decoded; and
transmitting a third data unit including a preamble, wherein the preamble includes a first STF, a first LTF, a signal field, a second STF, and a second LTF, and the third data unit includes second HARQ-related information indicating whether the third data unit includes retransmitted data, wherein the second HARQ-related information is included in the signal field of the preamble of the third data unit and the signal field includes a user field including a first subfield indicating a station identifier and a second subfield indicating the third data unit includes retransmitted data.
15 . The electronic device of claim 14 , wherein:
the first data unit includes a MAC header including a link adaptation control subfield including a first MCS (modulation and coding scheme) request (MRQ) subfield and a first MRQ sequence identifier (MSI) subfield,
the third data unit includes a MAC header including a link adaptation control subfield including a second MRQ subfield and a second MSI subfield,
the second MSI subfield set equal to a MSI value indicated by the first MSI subfield indicates that the third data unit includes retransmitted data, and
the second MSI subfield set different from a MSI value indicated by the first MSI subfield indicates that the third data unit does not include retransmitted data.
16 . A method performed by an electronic device, comprising:
receiving a first data unit including a first short training field (STF), a first long training field (LTF), a signal field, a second STF, a second LTF, and a data field including a first hybrid automatic repeat request (HARQ) unit;
transmitting a second data unit including first HARQ-related information indicating that the first HARQ unit fails to be decoded;
receiving a third data unit including a preamble, wherein the preamble includes a first STF, a first LTF, a signal field, a second STF, and a second LTF, and the third data unit includes second HARQ-related information indicating whether the third data unit includes retransmitted data, wherein the second HARQ-related information is included in the signal field of the preamble of the third data unit and the signal field includes a user field including a first subfield indicating a station identifier and a second subfield indicating the third data unit includes retransmitted data;
obtaining a second HARQ unit based on determination that the second HARQ-related information indicates that the third data unit includes retransmitted data; and
decoding the second HARQ unit with the first HARQ unit.