MIMO-OTFS Partial Loading for WLAN Coverage and Error Performance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing WLAN communication systems lack support for multistream transmission with OTFS and LDPC FEC, particularly in the context of partial loading, which is crucial for enhancing error performance and coverage.
Innovation Solution
A novel transmission methodology incorporating OTFS waveform with MIMO configuration, partial loading, and LDPC encoding, involving an OTFS grid with fewer QAM/PSK symbols, zero symbol loading, and advanced code block calculation methods to improve SNR and reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full loading of QAM/PSK symbols on OTFS grid is used, then data transmission rate is improved, but error performance and coverage deteriorate
Solution Approach 1:
The patent applies partial loading principle by transmitting only a subset of QAM/PSK symbols on the OTFS grid rather than filling all available grid points. Specifically, out of N×M total grid points, only K symbols are transmitted where K < N×M, creating a sparsely populated grid that improves error performance while maintaining reasonable data rates. This partial action resolves the contradiction by sacrificing some transmission capacity to gain reliability.
2Reliability
If OTFS modulation with partial loading is implemented, then SNR advantage and coverage enhancement are achieved, but system complexity increases
Solution Approach 1:
The patent segments the OTFS grid into multiple resource elements and selectively activates only certain portions for data transmission. The grid is divided into N×M points but only K points are used, creating a segmented resource allocation scheme. This segmentation simplifies the effective system complexity by deactivating unnecessary grid points while maintaining the core OTFS modulation framework for coverage enhancement.
Solution Approach 2:
The patent changes the loading factor parameter from full loading (K=N×M) to partial loading (K<N×M). By adjusting this parameter, the system can trade off between coverage enhancement and complexity. The partial loading parameter creates SNR advantages by reducing interference and noise accumulation, achieving coverage enhancement without requiring fundamental changes to the OTFS modulation structure.
3Reliability
If LDPC encoding with multistream transmission is added to OTFS, then error correction capability is improved, but computational complexity increases
Solution Approach 1:
The patent applies partial loading to the encoded symbol stream by transmitting only K symbols out of the total N×M grid points, even though LDPC encoding generates a full code block. This partial transmission approach reduces the effective computational complexity at the receiver while maintaining the error correction benefits of LDPC on the transmitted portion, resolving the contradiction between error correction capability and computational complexity.
Data Source
AI summary
The present invention discloses a communication system including WLAN communication systems comprising transmitter including an OTFS grid based Orthogonal Time Frequency Space (OTFS) waveform generator and Multiple Input Multiple Output (MIMO) streams. The transmitter comprises signal processor including OTFS modulator having FEC (forward error correction) encoder for pre-FEC bit appended input data stream and transmission of encoded input data stream in a selective sequence vide OTFS waveform modulated OTFS grid-partially loaded with QAM/PSK symbols of said encoded input data stream through MIMO transmitter and receiver streams including MIMO pre-coder based multi antenna support for said transmission and reception of said OTFS waveform thereby enabling OTFS waveform transmission and retrieval of input data stream.