Wireless Audio Packet FEC for Low-Latency Error Recovery

Solution Overview

Problem

Existing wireless audio stream transmission systems face challenges with reliability due to corrupted or dropped audio packets, which can lead to desynchronization of audio and video content, distortion, or delay in real-time audio, and inefficient use of wireless channel capacity.

Innovation Solution

The implementation of forward error correction (FEC) using parity blocks, where the number of source blocks and parity blocks is determined based on characteristics of the wireless communication protocol, such as timing information and packet scheduling, to reconstruct corrupted or dropped frames without re-transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If re-transmission of corrupted or dropped audio packets is implemented, then reliability of audio transport is improved, but audio content becomes de-synchronized with video content and real-time audio content becomes distorted or delayed

Engineering Contradiction:

Improvereliability of audio transportVSAvoidaudio playback delay

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The system performs preliminary action by generating forward error correction data blocks before transmission. These correction blocks are prepared in advance and transmitted alongside the audio data blocks, enabling the receiver to reconstruct corrupted packets without waiting for re-transmission, thus preventing playback delay while maintaining reliability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The forward error correction data blocks act as an intermediary that facilitates the reconstruction of corrupted audio packets. Instead of directly re-transmitting corrupted packets (which causes delay), the system uses pre-prepared correction blocks as a mediator to restore the original data at the receiver end, eliminating the need for time-consuming re-transmission cycles.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If re-transmission of corrupted or dropped audio packets is implemented, then reliability of audio transport is improved, but audio content becomes de-synchronized with video content

Engineering Contradiction:

Improvereliability of audio transportVSAvoidsynchronization between audio and video content

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The system performs preliminary action by generating forward error correction data blocks before transmission. These correction blocks are prepared in advance and transmitted alongside the audio data blocks, enabling the receiver to reconstruct corrupted packets without waiting for re-transmission, thus preventing playback delay while maintaining reliability.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The forward error correction data blocks act as an intermediary that facilitates the reconstruction of corrupted audio packets. Instead of directly re-transmitting corrupted packets (which causes delay), the system uses pre-prepared correction blocks as a mediator to restore the original data at the receiver end, eliminating the need for time-consuming re-transmission cycles.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Productivity

If forward error correction with parity blocks is implemented, then need for re-transmission is reduced and playback latency decreases, but wireless channel capacity is consumed by additional parity blocks

Engineering Contradiction:

Improveaudio stream transmission efficiencyVSAvoidwireless channel capacity

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The system applies parameter changes by dynamically adjusting the number of forward error correction data blocks based on the characteristics of the wireless communication channel. When the channel quality is good, fewer correction blocks are used, preserving channel capacity. When channel quality deteriorates, more correction blocks are allocated, maintaining audio reliability without wasting capacity when conditions are favorable.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system implements dynamics by making the forward error correction scheme adaptive rather than static. The number of parity blocks varies dynamically based on real-time assessment of wireless channel conditions, allowing the system to optimize the balance between error correction capability and channel capacity utilization according to current transmission conditions.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12348312B2Wireless transmission and reception of packetized audio data in combination with forward error correction

Publication Date: 2025.07.01 DOLBY INTERNATIONAL AB

AI summary

Methods for transmitting and receiving an audio stream are provided. For transmission, the method involves obtaining a frame of an audio signal, determining a number of source blocks to divide the frame of the audio signal into and a number of parity blocks to generate for forward error correction, wherein the number of source blocks and the number of parity blocks are determined based on characteristics of a wireless communication protocol to be used. The wireless communication protocol may be BLUETOOTH. The parity blocks are usable by a decoder to reconstruct one or more corrupted or missing source blocks and may be obtained by means of Reed-Solomon encoding.