Wireless Relay Station Network Coding Throughput

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Solution Overview

Problem

In wireless communication systems using network coding, the need to equalize packet lengths for network coding and the subsequent error correction encoding leads to inefficiencies, such as increased data length and reduced system throughput, as well as inability to adjust transmission quality for each destination.

Innovation Solution

A wireless relay station apparatus that selects and applies different coding rates for each packet based on required communication quality, generates error correction encoded packets of equal length, and uses concatenation bits to adjust packet lengths, enabling network encoding and transmission with improved quality and throughput.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If zero padding is performed to equalize packet lengths for network coding, then network coding can be performed, but the data length increases and system throughput decreases

Engineering Contradiction:
Improvecommunication qualityVSAvoidsystem throughput
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent changes the parameter of packet length by performing zero padding to equalize the lengths of first and second packets before network coding. This ensures that the coded packet maintains the same length as the original packets, preventing unnecessary data length increase and maintaining system throughput while enabling network coding operation.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If different coding rates are used for different packets, then transmission quality can be optimized for each destination, but packet lengths become unequal making network coding difficult

Engineering Contradiction:
Improvetransmission qualityVSAvoidpacket length equalization complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by adjusting the packet length through zero padding to equalize the lengths of packets that have been encoded with different coding rates. This allows the system to maintain different coding rates for optimized transmission quality while still achieving equal packet lengths required for network coding operation.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If packet lengths are equalized before error correction encoding, then network coding can be performed, but the ability to adjust transmission quality for each destination is lost

Engineering Contradiction:
Improvenetwork coding efficiencyVSAvoidtransmission quality adjustment capability
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent applies preliminary action by performing error correction encoding on the first and second packets with different coding rates before performing network coding. The zero padding for length equalization is then applied to the encoded packets. This sequence allows different coding rates to be applied for quality optimization while still enabling subsequent network coding operation.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2487808B1Wireless communication system, radio relay station apparatus, radio terminal station apparatus, and wireless communication method
Publication Date: 2018.11.14 NIPPON TELEGRAPH & TELEPHONE CORP
  • EP2487808B1 patent drawingFigure 1
  • EP2487808B1 patent drawingFigure 2
  • EP2487808B1 patent drawingFigure 3

AI summary

Provided is a wireless communication system employing network coding which can set transmission quality for each destination of packets and improve throughput. The wireless communication system is provided with a wireless relay station apparatus and wireless terminal station apparatuses. The wireless relay station apparatus selects coding rates to be used for a first packet and a second packet in accordance with communication quality required for the first packet and the second packet, generates error correction encoded packets having the same data length from the first packet and the second packet using the selected coding rates, performs network encoding on the error correction encoded first and second packets to generate a network encoded packet, and transmits the generated network encoded packet. The wireless terminal station apparatus performs error correction encoding on a third packet equal to one of the first and second packets, performs network decoding on a received network encoded packet using the error correction encoded third packet to generate a decoded packet, and performs error correction decoding.