Convolutional Deinterleaver Reconfiguration Without Extra Buffer Memory

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Solution Overview

Problem

Convolutional interleaving in digital communication systems faces challenges such as increased complexity and memory requirements, and the inability to change interleaver parameters without shutting down the system, which can lead to data loss or the need for transmitting dummy symbols.

Innovation Solution

A receiver with a convolutional deinterleaver that detects and compensates for discontinuity punctures by storing and reordering symbols using existing delay portion memories, allowing for reconfiguration and reduced memory usage without increasing latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If discontinuity punctures are introduced into the interleaved symbol stream to enable frame transitions, then the system gains flexibility to change interleaving parameters, but symbols become out of sequence in the deinterleaved stream requiring complex compensation mechanisms

Engineering Contradiction:

Improveflexibility to change interleaving parametersVSAvoidcomplexity of deinterleaver compensation mechanism

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The controller pre-identifies symbols that will be affected by discontinuity punctures before they are punctured. By calculating which symbols would be out of sequence based on the puncture pattern, the system prepares to compensate for these symbols in advance, ensuring correct deinterleaving order without complex real-time adjustments

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary buffer mechanism between the deinterleaver and the error correction decoder. This buffer stores identified symbols temporarily and releases them in the correct sequence, acting as a mediator that resolves the ordering problem caused by punctures without requiring complex modifications to the deinterleaver itself

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If a dedicated buffer is used to store all identified symbols affected by discontinuity punctures, then correct deinterleaved sequence is achieved, but memory requirements increase significantly

Engineering Contradiction:

Improvecorrectness of deinterleaved symbol sequenceVSAvoidmemory requirements

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

Instead of using a single large dedicated buffer to store all identified symbols, the patent segments the buffering function across multiple smaller delay portions. Each delay portion handles a specific segment of the symbol stream, and only the necessary symbols for compensation are stored in each segment, reducing the total memory requirement while maintaining correct sequence

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The delay portions in the deinterleaver are made multi-functional: they serve both their original purpose of delaying symbols for deinterleaving and the additional function of storing identified symbols affected by punctures. This eliminates the need for separate dedicated buffer memory, reducing overall memory requirements while achieving the same reliability goal

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Adaptability or versatility

If interleaving frame lengths are changed to improve system adaptability, then versatility increases, but latency through the deinterleaver varies requiring constant adjustment

Engineering Contradiction:

Improveability to change interleaving frame lengthsVSAvoidlatency variation through deinterleaver

Core Design Contradiction:

Adaptability or versatilityVSLoss of time

Solution Approach 1:

The patent implements a dynamic control mechanism where the controller adjusts the deinterleaver operation based on the current frame length. By dynamically modifying the delay amounts and symbol selection based on the active frame configuration, the system maintains constant latency through the deinterleaver even as frame lengths change, enabling versatility without time loss variation

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11303304B2Receiver receiving a signal including physical layer frames, and including a convolutional deinterleaver and a deinterleaver selector

Publication Date: 2022.04.12 SATURN LICENSING LLC

AI summary

A receiver is arranged for receiving a signal comprising an interleaved symbol stream. The receiver comprises a convolutional deinterleaver comprising a plurality of delay portions each of which is arranged to delay symbols from the symbol stream from an input to an output by a different amount, the delay portions being arranged in a sequence. An input selector is configured to input the symbols from the symbol stream to the delay portions so that successive symbols are input in accordance with the sequence of the delay portions. An output selector configured to read the symbols from the delay portions by successively selecting the symbols from the outputs of the delay portions in accordance with the sequence of the delay portions to form a deinterleaved symbol stream.