Polar Encoding and Perfect Shuffles in 5G Communication
Järvenpää, Matias (2023)
Järvenpää, Matias
2023
Tieto- ja sähkötekniikan kandidaattiohjelma - Bachelor's Programme in Computing and Electrical Engineering
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
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Hyväksymispäivämäärä
2023-12-19
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-2023121710938
https://urn.fi/URN:NBN:fi:tuni-2023121710938
Tiivistelmä
Digital communication is an essential part of today's society. Almost everyone has a mobile phone that is constantly wirelessly transmitting data using cellular network. To enable fast communication rates, efficient error control coding is needed. This thesis focuses on polar code, which is a linear block error-correcting code used for example in channel coding of the fifth-generation network technology, 5G.
The aim of this thesis is to present a parallel implementation of polar encoding according to the 5G New Radio (NR) specifications. To enable this implementation to be used on a Digital Signal Processor (DSP), certain instruction set extensions are needed. These custom instructions enable efficient computation, but they do come at a hardware cost, which is why the number of different custom instructions has been kept low. Implementations are proposed for frozen bit insertion, polar transform, and sub-block interleaving. All these procedures are parts of the 5G polar encoding chain.
The properties of a special permutation of bits called a perfect shuffle were found suitable for this implementation, and the permutation is used extensively in this thesis. Using a perfect shuffle to implement a butterfly-pattern based algorithm is not a new idea. In previous work it was shown that a perfect shuffle can be used for example in the implementation of Fast Fourier Transform (FFT). However, previous work using the perfect shuffle to implement polar encoding similarly as was done here was not found.
The perfect shuffle permutation used here can be compared to shuffling a pack of playing cards by dividing the deck into two halves and then releasing the two halves so that the cards in the two halves get interleaved. The properties of this perfect shuffle allow all the difficult bit-level addressing patterns found in the polar encoding process to be simplified to a regular structure easily implementable on a DSP. It is found that a single perfect shuffle permutation will allow the implementation of polar encoding for all different code block sizes defined in the 5G specification.
The aim of this thesis is to present a parallel implementation of polar encoding according to the 5G New Radio (NR) specifications. To enable this implementation to be used on a Digital Signal Processor (DSP), certain instruction set extensions are needed. These custom instructions enable efficient computation, but they do come at a hardware cost, which is why the number of different custom instructions has been kept low. Implementations are proposed for frozen bit insertion, polar transform, and sub-block interleaving. All these procedures are parts of the 5G polar encoding chain.
The properties of a special permutation of bits called a perfect shuffle were found suitable for this implementation, and the permutation is used extensively in this thesis. Using a perfect shuffle to implement a butterfly-pattern based algorithm is not a new idea. In previous work it was shown that a perfect shuffle can be used for example in the implementation of Fast Fourier Transform (FFT). However, previous work using the perfect shuffle to implement polar encoding similarly as was done here was not found.
The perfect shuffle permutation used here can be compared to shuffling a pack of playing cards by dividing the deck into two halves and then releasing the two halves so that the cards in the two halves get interleaved. The properties of this perfect shuffle allow all the difficult bit-level addressing patterns found in the polar encoding process to be simplified to a regular structure easily implementable on a DSP. It is found that a single perfect shuffle permutation will allow the implementation of polar encoding for all different code block sizes defined in the 5G specification.
Kokoelmat
- Kandidaatintutkielmat [8709]