Uplink Control Signal DTX Detection Using Codeword Likelihood Thresholds
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication systems face challenges in accurately detecting acknowledgment (ACK), negative acknowledgment (NACK), and discontinuous transmission (DTX) signals, particularly in small block code-based receivers where cyclic redundancy check (CRC) is not available, leading to false detections and resource wastage or data loss.
Innovation Solution
A method and device for processing uplink control information (UCI) signals that transform received signals into likelihood calculations of possible transmitted codewords, determining a maximum magnitude value, and comparing it to a scaled or unscaled threshold to differentiate between linear block encoded signals and DTX, enabling accurate ACK/NACK message generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional detection methods are used in small block code-based receivers without CRC, then the device complexity is reduced, but the measurement precision of ACK/NACK/DTX detection deteriorates leading to false detections
Solution Approach 1:
The patent changes the detection parameter from simple signal presence/absence to likelihood calculation based maximum magnitude comparison. By computing the maximum magnitude of likelihood values across all possible codewords and comparing it to a threshold, the system achieves reliable DTX detection without requiring complex CRC mechanisms, thus resolving the contradiction between device complexity and measurement precision.
2Ease of operation
If the eNodeB expects ACK/NACK symbols without considering DTX possibility, then the ease of operation is maintained, but the reliability of detection deteriorates due to false ACK/NACK detections
Solution Approach 1:
The patent applies preliminary action by performing likelihood calculation for all possible codewords before making the final detection decision. The maximum magnitude comparison is performed in advance to determine whether a valid signal is present before the eNodeB proceeds with ACK/NACK interpretation, thereby preventing false detections while maintaining operational simplicity.
3Loss of information
If DTX is wrongly detected as ACK, then the loss of information is minimized, but the productivity deteriorates due to unnecessary retransmissions and resource wastage
Solution Approach 1:
The patent implements feedback through the maximum magnitude comparison mechanism that provides reliable DTX detection feedback to the eNodeB. By accurately distinguishing between DTX and actual ACK/NACK signals, the system prevents unnecessary retransmissions and resource allocation, thereby maintaining high system throughput while avoiding data loss from incorrect detection.
Data Source
AI summary
Described is a method and device for processing a signal received at an uplink control information (UCI) receiver in a wireless communication system. The method comprises processing a signal received on an uplink (UL) at said UCI receiver to transform said received signal into a likelihood calculation of possible transmitted codewords (θ1 . . . θi . . . θN). The likelihood calculation of possible transmitted codewords (θ1 . . . θi . . . θN) may comprise a multi-dimensional discrete Fourier transform (DFT) (θ1 . . . θi . . . θN) of said received signal. The multi-dimensional may be formed as a Hadamard Transform. The method includes determining a maximum magnitude θmax value from said likelihood calculation of possible transmitted codewords (θ1 . . . θi . . . θN) and then comparing said θmax value to a selected, calculated or predetermined scaled threshold c·τ where τ is a threshold and c is a scaling factor for the threshold τ. The comparison is such that, where θmax>c·τ, it is determined that the signal received on the UL at said UCI receiver comprises a linear block encoded signal. In some cases, the scaling factor c may be omitted.