Puncture Position Detection in Convolutional Decoder Bit Streams
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Solution Overview
Problem
Existing communication systems face challenges in determining the puncture position for de-puncturing punctured convolutional codes without additional circuitry, leading to increased manufacturing costs and complex product designs.
Innovation Solution
An apparatus comprising a slicing unit, a delay line, a convolutional decoder, and a puncture decision unit is used to determine the detected puncture position by generating a puncture position signal, slicing received symbols, delaying the bit streams, and comparing error metrics to select the appropriate puncture position for de-puncturing and decoding processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If extra encode/puncture circuitry is added to determine puncture position, then puncture position detection accuracy is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
The system uses its own decoded output to verify and determine the puncture position. The decoder's output is fed back through the puncturing process, and the synchronized comparison between original and re-generated bit streams enables self-verification of puncture position without external assistance or additional dedicated circuitry.
Solution Approach 2:
The puncture position detection function is merged with the existing decoding and synchronization processes. The synchronization circuit that already exists for timing alignment is utilized to also perform the puncture position determination by comparing bit streams, eliminating the need for separate detection circuitry.
2Measurement precision
If extra encode/puncture circuitry is added to determine puncture position, then puncture position detection accuracy is improved, but manufacturing cost increases
Solution Approach 1:
The system uses its own decoded output to verify and determine the puncture position. The decoder's output is fed back through the puncturing process, and the synchronized comparison between original and re-generated bit streams enables self-verification of puncture position without external assistance or additional dedicated circuitry.
Solution Approach 2:
Existing circuit components are made multi-functional. The synchronization circuit performs both its original timing synchronization function and the additional puncture position detection function. The decoder and encoder circuits serve dual purposes of data processing and puncture position verification.
3Measurement precision
If synchronization delay is applied to bit streams, then timing alignment between bit streams is improved, but processing time increases
Solution Approach 1:
The delay line is configured to provide the exact synchronization delay needed in advance, based on the known puncture pattern structure. By pre-calculating and implementing the required delay amount, the system achieves proper timing alignment without iterative adjustment or excessive waiting time.
Solution Approach 2:
The system uses feedback from the comparison between the delayed first bit stream and the third bit stream to verify timing alignment. The error metric calculation provides feedback that confirms whether the synchronization delay is correct, enabling precise timing alignment while minimizing unnecessary delay.
Data Source
AI summary
An apparatus and method for determining a puncture position for a de-puncturing process. A stream of received symbols that corresponds to a code is received. A slicing unit slices the stream of received symbols to determine representative bits of the code to form a first bit stream. A delay line delays the first bit stream to generate a second bit stream. A convolutional decoder de-punctures and decodes the received symbol to generate a third bit stream. A puncture decision unit, coupled to the delay line and the convolutional decoder, selects the puncture position with one of possible puncture positions, and delivers the puncture position signal indicating the puncture position, and compares the second bit stream and the third bit stream to generate an error metric corresponding to the puncture position, and determines one of the possible puncture positions according to the error metric as a detected puncture position.