초록 ▼

Embodiments of the invention provide a system and method of hybrid automatic repeat-request (HARQ) processing. A viterbi decoder is coupled to and follows a descrambler. After the signal has been de-scrambled, it can be stored in a memory in case it needs to be recombined with another packet. This m

Embodiments of the invention provide a system and method of hybrid automatic repeat-request (HARQ) processing. A viterbi decoder is coupled to and follows a descrambler. After the signal has been de-scrambled, it can be stored in a memory in case it needs to be recombined with another packet. This means that the log-likelihood ratios LLRs for each transmitted bit are stored in memory using a finite number of bits (for example, between 4 and 12 bits). If the packet that is currently being processed contains retransmitted information, then the de-scrambled output stored from a previous packet containing the same information can be loaded and combined with the current packet.

대표청구항 ▼

1. A receiver for hybrid-automatic-repeat request (HARQ), comprising: a radio frequency (RF) front end;an analog-to-digital convertor (ADC);a synchronizer to remove cyclic prefix and for zero padding;a fast fourier transform (FFT);a frequency equalization (FEQ);a deinterleaver;a modified descrambler

1. A receiver for hybrid-automatic-repeat request (HARQ), comprising: a radio frequency (RF) front end;an analog-to-digital convertor (ADC);a synchronizer to remove cyclic prefix and for zero padding;a fast fourier transform (FFT);a frequency equalization (FEQ);a deinterleaver;a modified descrambler;a memory coupled to said descrambler;a combiner for combining transmissions; anda decoder coupled to and following said modified descrambler. 2. A method of retransmitting a packet after cyclically shifting a plurality of tones in a hybrid-automatic-repeat request (HARQ) scheme to create a plurality of frequency tone mappings, said method comprising: for a first retransmission, cyclically shifting data in a frequency-domain by one-half of a number of said plurality of tones;for a second retransmission, cyclically shifting data in the frequency-domain by one-quarter of a number said plurality of tones; andfor a third retransmission, cyclically shifting data in the frequency-domain by three-quarters of a number of data tones from said plurality of tones. 3. The method of claim 2, wherein said plurality of tones are in four groups and hybrid-automatic-repeat request (HARQ) scheme defined as follows: original packet transmission: Datai(m)⁡(t)=1N⁢∑k=0ND-1⁢si(m)⁡(Di(m)⁡(k))·exp⁡(j⁢⁢2⁢⁢π⁢⁢F·D0(m)⁡(k)·t)first packet retransmission: D1(m)⁡(k)=D0(m)⁡((k+12⁢ND)⁢mod⁢⁢ND)second packet retransmission: D2(m)⁡(k)=D0(m)⁡((k+14⁢ND)⁢mod⁢⁢ND)third packet retransmission: D3(m)⁡(k)=D0(m)⁡((k+34⁢ND)⁢mod⁢⁢ND). 4. The method of claim 2, wherein information comprising bits in header are used to communicate cyclic shift used on said plurality of tones. 5. The method of claim 3, wherein information comprising bits in header are used to communicate an order in which the four groups are transmitted. 6. The method of claim 2, wherein information comprising bits in header are used to communicate cyclic shift used on said plurality of tones. 7. The method of claim 3, wherein NACK messages from a receiver triggers changes in said frequency tone mappings for retransmissions.