MIMO Receiver Candidate Vector Selection for Low-Power LLR Processing
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Solution Overview
Problem
High-speed signal processing in modems for wireless communication networks leads to increased power consumption and heating, complicating the calculation of log likelihood ratios (LLR) in multiple input multiple output (MIMO) systems due to noise, which affects error correction reliability.
Innovation Solution
A MIMO receiver that selects a candidate vector set based on previously generated LLR information, calculating Euclidean distances for received symbols and using a vector set detector to optimize the LLR calculation process, reducing processing complexity and power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-speed signal processing is performed in MIMO modems, then data processing speed is improved, but power consumption and heating increase
Solution Approach 1:
The candidate vector set is divided into multiple subsets based on Euclidean distance metrics. The demodulator calculates Euclidean distances between received symbols and candidate vectors, then segments the full candidate set into multiple subsets (first candidate vector set, second candidate vector set, etc.) with different sizes. This segmentation allows selective processing of only relevant subsets, reducing overall computational load and power consumption while maintaining processing speed.
2Reliability
If LLR calculation is performed for all candidate vectors, then error correction reliability is improved, but processing complexity increases
Solution Approach 1:
Instead of calculating LLR for all candidate vectors, the system performs partial action by selecting and processing only the most relevant candidate vector subsets. The vector set detector identifies and selects subsets containing candidate vectors with smaller Euclidean distances to received symbols, performing LLR calculation only on these selected subsets. This partial processing maintains sufficient error correction reliability while significantly reducing processing complexity.
3Measurement precision
If candidate vector set size is increased, then LLR calculation accuracy is improved, but processing time and power consumption increase
Solution Approach 1:
The system performs preliminary action by pre-calculating and storing Euclidean distances between candidate vectors and received symbols before LLR calculation. Based on these pre-computed distance metrics, the vector set detector preliminarily identifies and selects the most relevant candidate vector subsets. This preliminary selection process enables subsequent LLR calculation to be performed quickly on a reduced set of vectors, maintaining accuracy while reducing processing time.
Data Source
AI summary
A receiver for receiving a signal including a plurality of symbols through a multiple input multiple output (MIMO) channel, and an operation method of the receiver are provided. The receiver includes a demodulator configured to calculate, for each physical channel, Euclidean distances of one or more of the received symbols with respect to all candidate vectors included in an initial candidate vector set and to output information about the Euclidean distances. A vector set detector may select, based on the information, one of a plurality of candidate vector sets having different sizes, as a subsequent candidate vector set for calculating a log likelihood ratio (LLR) of other symbols of the plurality of symbols or an LLR with respect to a second signal received following the first signal.