I don't have any experties to explain the channel coding algorithm in detail not to mention of explanining it in plain / intuitive way. So this page will describe only on high level descriptions of NR channel coding as I learn more on this.

Channel coding is a fundamental part of wireless communication systems. It introduces redundancy to transmitted data to enable error detection and correction, which is crucial for reliable communication over noisy channels.

• In LTE:
• Turbo Coding and Convolutional Coding are predominantly used.
• These techniques offer strong error correction but have limitations in terms of scalability and complexity for larger block sizes.
• In NR
• Polar Coding and LDPC (Low-Density Parity-Check) Coding replace Turbo and Convolutional Coding due to their better performance and efficiency for 5G use cases.
• NR’s choice of Polar and LDPC coding ensures better performance for 5G applications, where large data blocks and high reliability are critical.
• The modularity in UCI coding (Repetition, Simplex, Reed-Muller) reflects a tailored approach to different payload sizes.
• While encoding in LDPC is complex, its advantages in decoding make it the preferred choice for high-throughput data channels.

Channel Coding Algorithms in NR

Below is a breakdown of the channel coding algorithms used in NR for various data types, along with their characteristics:

Basically Polar Coding is to replace TBCC (Tail Bit Convolution Code) and LDPC is to replace Turbo Coding.

Turbo Coding is relatively simple at Encoding phase but complex in decoding phase. This complexity gets higher as the size of code block gets larger.

LDPC is not as simple as turbo coding at Encoding phase, but much simpler in decoding phase. So good for large block size.  

Below is the brief descriptions for each coding techniques

• Polar Coding:
• Purpose: Replaces TBCC (Tail-Biting Convolutional Code) used in LTE.
• Advantages:
• Highly efficient for small block sizes.
• Performance improves as block size increases.
• Excellent for control channels due to its capacity-achieving properties under successive cancellation decoding.
• Applications: BCH, DCI, and certain UCI payloads.
• Repetition Code:
• Purpose: Simplest form of error correction, repeating each bit multiple times to ensure reliability.
• Applications: UCI with minimal payload (e.g., 1 bit).
• Simplex Code:
• Purpose: A lightweight code for small payloads like 2 bits of UCI, providing moderate error correction capability.
• Reed-Muller Code:
• Purpose: Used for moderate payload sizes in UCI (3 to 11 bits).
• Advantages: Balances simplicity and error correction performance.
• LDPC Coding:
• Purpose: Replaces Turbo Coding for data channels like DL-SCH and UL-SCH.
• Advantages:
• Complexity shifts towards encoding rather than decoding, making it scalable for high throughput and large block sizes.
• Decoding is simpler and well-suited to hardware implementation.
• Achieves near-Shannon limit performance with iterative decoding algorithms.

Comparison with LTE Channel Coding

The evolution from LTE to NR (New Radio) brought significant advancements in channel coding techniques to meet the demanding requirements of 5G networks. In LTE, Turbo Coding and Convolutional Coding were predominantly used, offering good performance for error correction but facing limitations in scalability and complexity, particularly with larger block sizes. NR introduces Polar Coding and LDPC (Low-Density Parity-Check) Coding as replacements, ensuring improved efficiency, scalability, and performance. Polar Coding excels in small block sizes, making it ideal for control channels, while LDPC is optimized for large data blocks, providing near-optimal error correction with lower decoding complexity. This shift highlights the enhanced adaptability and robustness of NR coding schemes compared to those in LTE.

Reference

• 5G NR - A New Era for Enhanced Mobile Broadband (Mediatek)