Flexible rate matching
View Patent ↗Flexible rate matching. No constraints or restrictions are placed on a sending communication device when effectuating rate matching. The receiving communication device is able to accommodate received transmissions of essentially any size (e.g., up to an entire turbo codeword that includes all systematic bits and all parity bits). The receiving communication device employs a relatively small-sized memory to ensure a lower cost, smaller sized communication device (e.g., handset or user equipment such as a personal wireless communication device). Moreover, incremental redundancy is achieved in which successive transmissions need not include repeated information therein (e.g., a second transmission need not include any repeated information from a first transmission). Only when reaching an end of a block of bits or codeword to be transmitted, and when wrap around at the end of such block of bits or codeword occurs, would any repeat of bits be incurred within a later transmission.
1. An apparatus, comprising:
an input to receive a first signal, transmitted to the apparatus from at least one additional apparatus, from a communication channel;
a demodulator to process the first signal to generate a first plurality of log-likelihood ratios (LLRs);
a buffer, having a storage capacity less than all of the first plurality of LLRs, to store a first subset of the first plurality of LLRs that is less than all of the first plurality of LLRs; and
an output to output a first plurality of hard decisions based on a second subset of the first plurality of LLRs; and wherein:
the apparatus to transmit a re-transmission request to the at least one additional apparatus for the at least one additional apparatus to transmit at least one additional signal, corresponding to the first subset of the first plurality of LLRs stored within the buffer, to the apparatus;
the input to receive a second signal, transmitted to the apparatus from the at least one additional apparatus, from the communication channel;
the demodulator to process the second signal to generate a second plurality of LLRs;
the buffer to store a first subset of the second plurality of LLRs; and
the output to output a second plurality of hard decisions based on a second subset of the second plurality of LLRs.
2. The apparatus of claim 1 , further comprising:
a turbo decoder:
to process the first plurality of LLRs to generate the first plurality of hard decisions; and
to process the second plurality of LLRs to generate the second plurality of hard decisions; and
a cyclic redundancy check (CRC) check module to:
perform a first CRC check on the first plurality of hard decisions to identify the first subset of the first plurality of LLRs and the second subset of the plurality of LLRs; and
perform a second CRC check on the second plurality of hard decisions to identify the first subset of the second plurality of LLRs and the second subset of the second plurality of LLRs.
3. The apparatus of claim 1 , further comprising:
an LLR combining module to update or modify at least one LLR of the first subset of the first plurality of LLRs based on at least one LLR of the first subset of the second plurality of LLRs.
4. The apparatus of claim 1 , wherein:
the first subset of the first plurality of LLRs corresponding to those LLRs from the first plurality of LLRs in accordance with a predetermined, non-consecutive pattern.
5. The apparatus of claim 1 , wherein:
the apparatus being a communication device operative within at least one of a satellite communication system, a wireless communication system, a wired communication system, and a fiber-optic communication system.
6. An apparatus, comprising:
an input to receive a signal from a communication channel;
a demodulator to process the signal to generate a plurality of log-likelihood ratios (LLRs);
a buffer, having a storage capacity less than all of the plurality of LLRs, to store a first subset of the plurality of LLRs that is less than all of the plurality of LLRs; and
an output to output a plurality of hard decisions based on a second subset of the plurality of LLRs.
7. The apparatus of claim 6 , further comprising:
a turbo decoder to process the plurality of LLRs to generate the plurality of hard decisions; and
a cyclic redundancy check (CRC) check module to perform a CRC check on the plurality of hard decisions to identify the first subset of the plurality of LLRs and the second subset of the plurality of LLRs.
8. The apparatus of claim 6 , wherein:
the signal is transmitted to the apparatus from at least one additional apparatus; and
the apparatus to transmit a re-transmission request to the at least one additional apparatus for the at least one additional apparatus to transmit at least one additional signal, corresponding to the first subset of the plurality of LLRs stored within the buffer, to the apparatus.
9. The apparatus of claim 8 , wherein:
the signal is transmitted to the apparatus from at least one additional apparatus;
the apparatus to transmit a re-transmission request to the at least one additional apparatus for the at least one additional apparatus to transmit at least one additional signal, corresponding to the first subset of the plurality of LLRs stored within the buffer, to the apparatus; and
a demodulator to process the at least one additional signal to generate at least one additional plurality of LLRs.
10. The apparatus of claim 8 , wherein:
the signal is transmitted to the apparatus from at least one additional apparatus;
the apparatus to transmit a re-transmission request to the at least one additional apparatus for the at least one additional apparatus to transmit at least one additional signal, corresponding to the first subset of the plurality of LLRs stored within the buffer, to the apparatus;
the demodulator to process the at least one additional signal to generate at least one additional plurality of LLRs; and further comprising:
a turbo decoder to process the at least one additional plurality of LLRs to generate at least one additional plurality of hard decisions; and
a cyclic redundancy check (CRC) check module to perform a CRC check on the at least one additional plurality of hard decisions to identify a first subset of the at least one additional plurality of LLRs and a second subset of the plurality of LLRs; and wherein:
the buffer to store the first subset of the at least one additional plurality of LLRs; and
the output to output a subset of the at least one additional plurality of hard decisions based on the at least one additional plurality of LLRs.
11. The apparatus of claim 6 , wherein:
the signal is transmitted to the apparatus from at least one additional apparatus;
the apparatus to transmit a re-transmission request to the at least one additional apparatus for the at least one additional apparatus to transmit at least one additional signal, corresponding to the first subset of the plurality of LLRs stored within the buffer, to the apparatus; and
a demodulator to process the at least one additional signal to generate at least one additional plurality of LLRs; and further comprising:
an LLR combining module to update or modify at least one LLR of the first subset of the plurality of LLRs based on at least one LLR of the at least one additional plurality of LLRs.
12. The apparatus of claim 6 , wherein:
the first subset of the plurality of LLRs corresponding to those LLRs from the plurality of LLRs in accordance with a predetermined, non-consecutive pattern.
13. The apparatus of claim 6 , wherein:
the apparatus being a communication device operative within at least one of a satellite communication system, a wireless communication system, a wired communication system, and a fiber-optic communication system.
14. A method for operating a communication device, the method comprising:
via an input of the communication device, receiving a signal from a communication channel;
processing the signal to generate a plurality of log-likelihood ratios (LLRs);
within a buffer of the communication device, having a storage capacity less than all of the plurality of LLRs, storing a first subset of the plurality of LLRs that is less than all of the plurality of LLRs; and
outputting a plurality of hard decisions based on a second subset of the plurality of LLRs.
15. The method of claim 14 , further comprising:
process the plurality of LLRs in accordance with turbo decoding to generate the plurality of hard decisions; and
performing a CRC check on the plurality of hard decisions to identify the first subset of the plurality of LLRs and the second subset of the plurality of LLRs.
16. The method of claim 14 , further comprising:
receiving the signal from at least one additional communication device;
transmitting a re-transmission request to the at least one additional communication device for the at least one additional communication device to transmit at least one additional signal, corresponding to the first subset of the plurality of LLRs stored within the buffer, to the communication device.
17. The method of claim 14 , further comprising:
receiving the signal from at least one additional communication device;
transmitting a re-transmission request to the at least one additional communication device for the at least one additional communication device to transmit at least one additional signal, corresponding to the first subset of the plurality of LLRs stored within the buffer, to the communication device; and
processing the at least one additional signal to generate at least one additional plurality of LLRs.
18. The method of claim 14 , further comprising:
receiving the signal from at least one additional communication device;
transmitting a re-transmission request to the at least one additional communication device for the at least one additional communication device to transmit at least one additional signal, corresponding to the first subset of the plurality of LLRs stored within the buffer, to the communication device;
processing the at least one additional signal to generate at least one additional plurality of LLRs; and
updating or modifying at least one LLR of the first subset of the plurality of LLRs based on at least one LLR of the at least one additional plurality of LLRs.
19. The method of claim 14 , wherein:
the first subset of the plurality of LLRs corresponding to those LLRs from the plurality of LLRs in accordance with a predetermined, non-consecutive pattern.
20. The method of claim 14 , wherein:
the communication device operative within at least one of a satellite communication system, a wireless communication system, a wired communication system, and a fiber-optic communication system.