Turbo Decoder Sequence Inversion to Eliminate Deinterleaving

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Solution Overview

Problem

Conventional turbo decoding methods require deinterleaving and rearrangement of data, which prolongs decoding processing time and reduces repeat control accuracy due to the need for larger memory and inefficient processing time for CRC checks.

Innovation Solution

A decoding device and method that decodes the second element code E′ followed by the first element code E, allowing for direct hard decision on the first soft-output data without deinterleaving, thereby omitting unnecessary processing steps and reducing decoding time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If conventional turbo decoding methods are used with deinterleaving and rearrangement, then decoding can be performed, but decoding processing time is prolonged

Engineering Contradiction:

Improvedecoding processing timeVSAvoiddecoding speed

Core Design Contradiction:

Loss of timeVSProductivity

Solution Approach 1:

The patent inverts the conventional decoding sequence by decoding the second element code E' first (which was interleaved) and then decoding the first element code E. This inversion eliminates the need for deinterleaving operations that normally would be required after decoding E, thereby reducing processing time and improving decoding speed without sacrificing correctness.

Inventive Principle:

Principle #13The other way round (Inversion)

2Reliability

If deinterleaving and rearrangement are performed in conventional decoding, then data can be processed correctly, but memory requirements increase

Engineering Contradiction:

Improvedecoding accuracyVSAvoidmemory capacity

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

By inverting the decoding order to process E' before E, the patent eliminates the need for storing and manipulating interleaved data structures in memory. The decoder processes the interleaved code E' directly without requiring large memory buffers for deinterleaving operations, thus reducing memory capacity requirements while maintaining decoding accuracy through the inverted processing sequence.

Inventive Principle:

Principle #13The other way round (Inversion)

3Loss of time

If conventional decoding with full deinterleving is used, then complete decoding is achieved, but power consumption increases

Engineering Contradiction:

Improvedecoding completionVSAvoidpower consumption

Core Design Contradiction:

Loss of timeVSUse of energy by moving object

Solution Approach 1:

The inverted decoding approach processes E' first and then E, eliminating the computationally intensive deinterleving and rearrangement operations that consume significant power in conventional decoders. This sequence reduction directly lowers power consumption while still achieving complete and accurate decoding of both element codes.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent extracts and eliminates the unnecessary deinterleving and rearrangement steps from the conventional decoding process. By removing these redundant operations that do not contribute to the final decoding result when using the inverted sequence, the patent reduces computational load and thereby decreases power consumption in mobile communication devices.

Inventive Principle:

Principle #2Taking out (Extraction)

Data Source

PatentUS7584409B2Method and device for alternately decoding data in forward and reverse directions

Publication Date: 2009.09.01 RENESAS ELECTRONICS CORP

AI summary

A decoding device according to the one embodiment of the invention includes: a first decoder performing a first decoding based on first encoded data obtained by encoding unencoded data, and second soft-output data to generate first soft-output data; a second decoder performing a second decoding based on second encoded data obtained by interleaving the unencoded data and encoding the interleaved data, and the first soft-output data to generate the second soft-output data; and a hard decision part outputting decoded data through hard decision on the first soft-output data.