Turbo Code Decoding with Early CRC Checks for Lower Latency
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Solution Overview
Problem
Turbo code-based communication systems face long decoding latency due to the need for multiple iterations to achieve an acceptable bit error rate, which is inefficient and increases complexity.
Innovation Solution
Implementing an error detection mechanism using a probability indicator and cyclic redundancy check (CRC) codes to determine if errors have occurred during transmission, allowing for early termination of decoding iterations or requesting retransmissions, thereby reducing the number of necessary iterations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple iterations of Turbo Code decoding are performed to achieve acceptable bit error rate, then reliability is improved, but decoding latency increases
Solution Approach 1:
The patent applies preliminary action by performing error detection using CRC codes after a predetermined number of decoding iterations (e.g., after 1 iteration) before completing the full decoding process. This allows the system to detect errors early and terminate further iterations unnecessarily, thereby reducing decoding latency while maintaining reliability through the preliminary error check.
2Loss of time
If error detection mechanism is implemented using CRC codes, then decoding latency is reduced, but device complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the decoding process into distinct stages: initial Turbo Code decoding iterations, intermediate error detection using CRC codes, and conditional termination or continuation. This segmentation allows the system to check for errors at intermediate points without requiring complete decoding, thereby reducing latency while managing complexity through structured process division.
3Productivity
If early termination of decoding iterations is implemented, then productivity is improved, but measurement precision worsens
Solution Approach 1:
The patent applies feedback by using CRC error detection results to control the continuation or termination of decoding iterations. The feedback mechanism provides information about whether errors are present in the decoded data, allowing the system to make informed decisions about whether additional iterations are necessary, thereby balancing productivity improvement with maintained error detection accuracy.
Data Source
AI summary
A method and a decoder for receiving a message encoded in Turbo Codes and modulated for transmission as an analog signal includes: (a) demodulating the analog signal to recover the Turbo Codes; and (b) decoding the Turbo Codes to recover the message using an iterative Turbo Code decoder, wherein the decoding includes performing an error detection after a predetermined number of iterations of the Turbo Code decoder to determine whether or not an error has occurred during the transmission. The predetermined number of iterations may be, for example, two. Depending on the result of the error detection, the decoding may stop, a request for retransmission of the message may be sent, or further iterations of decoding in the Turbo Code decoder may be carried out.