MIMO Precoding With LDPC Codeword Length Adjustment
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Solution Overview
Problem
Implementing the MIMO scheme effectively when a coding scheme such as LDPC coding is applied, as existing methods face challenges in optimizing data processing and transmission.
Innovation Solution
A data processing scheme that includes an encoding step for outputting a K-bit information bit sequence, a mapping step for generating complex signals, and a bit length adjustment step to ensure the bit length of the second bit sequence is a multiple of X+Y, facilitating the MIMO scheme's implementation with LDPC coding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If LDPC coding is applied to MIMO transmission, then error correction capability is improved, but bit sequence length compatibility becomes problematic
Solution Approach 1:
The patent segments the bit sequence processing into distinct stages: LDPC encoding produces an N-bit codeword, which is then divided into multiple complex signals (s1, s2, etc.) with specific bit allocations (X bits for s1, Y bits for s2). This segmentation allows the system to handle the large N-bit codeword in manageable portions that are compatible with MIMO transmission requirements.
Solution Approach 2:
The patent dynamically adjusts bit allocation parameters (X and Y) to ensure that the total bit length from LDPC encoding (N bits) is properly distributed among multiple complex signals. The bit length adjustment step modifies parameters to make the second bit sequence length a multiple of (X+Y), enabling flexible adaptation to different MIMO configurations while maintaining LDPC coding benefits.
2Adaptability or versatility
If bit sequence is adjusted to match MIMO requirements, then transmission compatibility is improved, but processing steps increase
Solution Approach 1:
The patent performs bit length adjustment as a preliminary action between LDPC encoding and MIMO mapping. By adjusting the bit sequence length to be a multiple of (X+Y) before the mapping step, the system ensures compatibility with MIMO transmission requirements upfront, preventing downstream processing issues and reducing the need for complex real-time adjustments during transmission.
3Productivity
If multiple complex signals are generated from encoded bits, then data transmission rate is improved, but mapping complexity increases
Solution Approach 1:
The patent assigns different bit lengths (X and Y) to different complex signals (s1 and s2) based on their specific transmission requirements. This local quality approach allows each complex signal to be optimized for its particular role in the MIMO transmission, with bit allocations that reflect the specific demands of each signal stream while maintaining overall system efficiency.
Data Source
AI summary
An encoder outputs a first bit sequence having N bits. A mapper generates a first complex signal s1 and a second complex signal s2 with use of bit sequence having X+Y bits included in an input second bit sequence, where X indicates the number of bits used to generate the first complex signal s1, and Y indicates the number of bits used to generate the second complex signal s2. A bit length adjuster is provided after the encoder, and performs bit length adjustment on the first bit sequence such that the second bit sequence has a bit length that is a multiple of X+Y, and outputs the first bit sequence after the bit length adjustment as the second bit sequence. As a result, a problem between a codeword length of a block code and the number of bits necessary to perform mapping by a set of modulation schemes is solved.