Enhanced grant detection method
View Patent ↗A method and system to reduce a probability of incorrect interruption of an uplink transmission of a wireless device are disclosed. According to one aspect, decoding of a sequence of bits obtained from a signal received by the wireless device is performed without knowing whether the sequence corresponds to one of a grant for uplink transmission and noise. Decoding of the sequence of bits is performed to determine a probability metric associated with a first m bits of the sequence, where m is an integer greater than 1. The probability metric is compared to a threshold. The received signal is interpreted as having a grant sequence if the probability metric is greater than the threshold. The received signal is interpreted as noise if the probability metric is not greater than the threshold.
1. A method to reduce a probability of incorrect interruption of an uplink transmission of a wireless device, the method comprising:
performing decoding of a sequence of bits obtained from a signal received by the wireless device, without knowing whether the sequence corresponds to one of a grant for uplink transmission and noise, to determine a probability metric associated with a first m bits of the sequence, where m is an integer greater than 1;
comparing the probability metric to a threshold;
treating the received signal as having a grant sequence if the probability metric is greater than the threshold;
if the probability metric is greater than the threshold, then determining if a cyclic redundancy code, CRC, check is positive, a positive CRC check indicating that the grant sequence is for the wireless device, and a negative CRC check indicating that the grant sequence is for a different wireless device; and
treating the received signal as noise if the probability metric is not greater than the threshold, wherein the probability metric is a log-likelihood metric given by: Λ(yi)=Log (Prob(yi=1)/Prob(yi=−1)) Vi=1 . . . m
where y is a sequence of bits obtained from the signal received by the wireless device and the probability metric being greater than the threshold is defined by the condition D={Λ(yi)>T ∀i=1 . . . m} where T is the threshold.
2. A wireless device, comprising:
a memory configured to store:
executable program code;
a sequence of bits obtained from a received signal; and
a threshold; and
a processor in communication with the memory, the processor configured to execute the executable program code to:
decode the sequence of bits obtained from the received signal, without knowing whether the sequence corresponds to one of a grant for uplink transmission and noise, to determine a probability metric associated with receiving a first m bits of the sequence, where m is an integer greater than 1;
compare the probability metric to the threshold;
determine that the received signal has a grant sequence if the probability metric is greater than the threshold; and
determine that the received signal is noise if the probability metric is not greater than the threshold, wherein, when the processor determines that the received signal has a grant sequence, the processor is further configured to perform a cyclic redundancy code, CRC, check to determine whether a CRC check is positive, a positive CRC check indicating that the grant sequence is for the wireless device, and a negative CRC check indicating that the grant sequence is for a different wireless device, and wherein the probability metric is a log-likelihood metric given by: Λ(yi)=Log (Prob(yi=1)/Prob(yi=−1)) Vi=1 . . . m where y is a sequence of bits obtained from the signal received by the wireless device and the probability metric being greater than the threshold is defined by the condition D={Λ(yi)>T∀i=1 . . . m} where T is the threshold.