LDPC PPDU Encoding with Longer Codewords for 320 MHz Wi‑Fi
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Solution Overview
Problem
The introduction of new codeword lengths in LDPC codes for higher bandwidth operations in Wi-Fi networks requires updates to the encoding mechanisms to maintain error correction efficiency and adapt to increased bandwidths up to 320 MHz, as existing mechanisms are not optimized for these longer codewords.
Innovation Solution
The proposed solution involves updating the LDPC PPDU encoding process by computing the number of LDPC codewords and their lengths, performing padding and puncturing operations, and distributing shortening, puncturing, and repeating bits among the codewords to accommodate codeword lengths of 3888 and 7776 bits, ensuring efficient encoding and decoding across various bandwidths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If existing LDPC encoding mechanisms are used, then the system operates reliably within traditional bandwidth limits, but it cannot efficiently support higher bandwidth operations up to 320 MHz
Solution Approach 1:
The patent implements dynamic selection of LDPC codeword lengths (1944, 3888, or 7776 bits) based on the available bandwidth and channel conditions. The encoding mechanism adapts its parameters in real-time, transitioning from static to dynamic operation to support bandwidths from traditional limits up to 320 MHz, thereby resolving the contradiction between adaptability and complexity.
Solution Approach 2:
The patent changes key parameters of the LDPC encoding mechanism, specifically the codeword length and the number of codewords, to match different bandwidth requirements. By adjusting these parameters dynamically, the system achieves high adaptability across various bandwidth scenarios without requiring a completely new encoding framework, thus managing complexity while improving versatility.
2Reliability
If longer LDPC codeword lengths are introduced for higher bandwidth, then error correction efficiency improves, but the encoding and decoding complexity increases
Solution Approach 1:
The patent segments the transmission data into multiple LDPC codewords, where the number of codewords and their individual lengths are selected from standardized sets (1944, 3888, 7776 bits). This segmentation approach allows the system to achieve high error correction efficiency for long total codeword lengths while maintaining manageable complexity by processing standardized blocks rather than arbitrary long sequences.
Solution Approach 2:
The patent utilizes predefined parameter sets for LDPC encoding, where codeword lengths and rates are standardized. This allows the system to achieve high reliability through longer effective codewords while controlling complexity by relying on standardized parameter configurations rather than custom encoding designs for each scenario.
3Productivity
If the number of LDPC codewords is increased to accommodate more data, then data throughput increases, but the overhead for managing and synchronizing codewords increases
Solution Approach 1:
The patent employs a universal signaling mechanism that can indicate the number and length of LDPC codewords using the same framework regardless of the specific bandwidth or data volume. This multi-functional approach allows the system to scale data throughput by adjusting codeword quantities while using a single management protocol, thereby reducing overhead complexity.
Solution Approach 2:
The patent performs preliminary determination of the number of LDPC codewords and their lengths based on pre-established mappings between bandwidth, modulation order, and codeword parameters. This preliminary action allows the system to configure the transmission parameters before actual data encoding, reducing runtime management overhead and simplifying synchronization.
Data Source
AI summary
An apparatus and method of encoding Low-Density Parity Check (LDPC) Physical Layer Convergence Protocol (PLCP) packet protocol data units (PPDU) is disclosed. For LDPC codeword of lengths 3888 and/or 7776, the number and length of codewords to use may depend on the number of available bits. In this case, if the number of available bits is larger than 1944 and less than 2596, two codewords of length 1944 or a single codeword of length 3888 to encode the PPDU is used to encode the PPDU. For larger numbers of available bits, one or more codewords of length 3888 or 7776 is used to encode the PPDU. Shortening and/or puncturing, when used, is also based on the number of available bits.