System and method for apriori decoding
Embodiments are provided for transmitting channel information, such as control channel information, using lower resources at the transmitter combined with using apriori information associated with channel information in the decoder of the receiver. The apriori information represent predictable information that can be predicted by the receiver and is not transmitted with the channel information by the transmitter. The transmitter determines the apriori information for the channel and codes the channel information into bits and fields excluding the apriori information. Upon receiving the channel information, the receiver determines the apriori information associated in accordance with previously received information. The apriori information is then provided as probability information for input to the decoder. The decoder then decodes the received information in accordance with the apriori information.
1. A method by a receiver for utilizing apriori information in a decoder, the method comprising:
receiving, at an input of the receiver, information associated with a control channel;
determining the apriori information in accordance with the received information and previously received information associated with the control channel; and
decoding the received information at the decoder using the determined apriori information as probability information.
2. The method of claim 1 , wherein the received information is decoded using a decoding scheme in accordance with a transmission rate of the received information.
3. The method of claim 1 , wherein the apriori information associated with the received information is determined in accordance with at least one of bits in the received information, prior received channel bits, prior decoded channel bits, and channel statistics.
4. The method of claim 1 further comprising:
receiving subsequent information;
detecting change in transmission behavior of the subsequent information in comparison to the received information; and
decoding the subsequent information without determining and using apriori information for the subsequent information.
5. The method of claim 4 , wherein the change in transmission behavior is a reduction of a modulation and coding scheme (MCS) in comparison to the received information.
6. The method of claim 4 , wherein the change in transmission behavior is a change of a modulation and coding scheme (MCS) in comparison to the received information.
7. The method of claim 1 , wherein the apriori information is determined and provided to the decoder upon detecting a higher modulation and coding scheme (MCS) for the received information in comparison to previously received information.
8. The method of claim 1 , wherein determining the apriori information comprises:
calculating probabilities corresponding to the received information; and
applying weights to bits in decoding the received information, wherein the weights are log likelihood ratios (LLRs).
9. The method of claim 1 , wherein the apriori information is determined using an auto-regression model where a probability function of a value of bits is equal to a sliding window average of the value.
10. The method of claim 1 , wherein the apriori information is determined using a conditional probability model comprising a plurality of bit transition states, and wherein the bit transition states are selected as probabilities using an appropriate sliding window.
11. The method of claim 1 , wherein the apriori information includes a probability value of predictable information.
12. The method of claim 1 , wherein the received information has a transmission rate of information bits to transmitted bits that is greater than 1.
13. The method of claim 1 , wherein the apriori information is determined and provided to the decoder upon detecting a change in a modulation and coding scheme (MCS) for the received information in comparison to previously received information.
14. The method of claim 1 , wherein the information, as received, is encoded into bits and fields excluding the apriori information.
15. The method of claim 14 , wherein the received information includes forward error correction (FEC) bits in accordance with the apriori information and with the bits and fields of the information.
16. The method of claim 1 , wherein the information, as received, is encoded into bits and fields by excluding a portion of the information predictable based on the apriori information.
17. The method of claim 16 , wherein the portion of the information predictable based on the apriori information includes at least one of a bit for indicating frequency hopping in transmission, a field for resource block allocation, a field for indicating a modulation and coding scheme in the transmission, a bit for indicating new data in the transmission, and a field for indicating transmission power control (TPC).
18. The method of claim 17 , wherein the apriori information includes probabilities values for matching the bits and fields in the portion predictable based on the apriori information to previously transmitted information.
19. A network component for utilizing apriori information, the network component comprising:
at least one processor including a decoder; and
a non-transitory computer readable storage medium storing programming for execution by the processor, the programming including instructions to:
receive, at an input, information associated with a control channel;
determine the apriori information in accordance with the received information and previously received information associate with the control channel; and
decode the received information at the decoder using the determined apriori information as probability information.
20. The network component of claim 19 , wherein the received information corresponds to bits and fields in a Long Term Evolution (LTE) Format 0, a Physical Downlink Control Channel (PDCCH), a Physical Uplink Shared Channel (PUSCH), a Physical Downlink Shared Channel (PDSCH), a Physical Broadcast Channel (PBCH), a Downlink Shared Channel (DSCH), or a wireless local area network (WLAN) control channel.
21. The network component of claim 19 , wherein the network component is a user equipment (UE) or a base station (BS).