Channel Adaptive Sphere Detector for Signal Correlation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current communication systems face inefficiencies in signal detection, as sphere detectors provide better bit error rate (BER) performance for highly correlated signals but require more calculations and power, while MMSE detectors conserve power but perform poorly in such conditions, necessitating a method to switch between detection types based on signal correlation.

Innovation Solution

A channel adaptive system that determines the correlation factor of received signals and switches between MMSE and sphere detectors, using a listed based log likelihood ratio (LLR) generator for sphere detection when correlation exceeds a threshold and an MMSE LLR generator otherwise, optimizing detection performance and power consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a sphere detector is used for signal detection, then bit error rate performance is improved for highly correlated signals, but calculation complexity and power consumption increase

Engineering Contradiction:
Improvebit error rate performanceVSAvoidcalculation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The system dynamically switches between sphere detector and MMSE detector based on the calculated correlation factor of the channel. When the correlation factor exceeds a threshold, the sphere detector is activated to improve BER performance; otherwise, the computationally simpler MMSE detector is used. This dynamic adaptation resolves the contradiction by making detection complexity conditional rather than fixed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the detection parameter (detector type) based on the channel correlation parameter. By monitoring the correlation factor and adjusting the detector selection accordingly, the system optimizes the balance between BER performance and calculation complexity according to actual channel conditions.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a sphere detector is used for signal detection, then bit error rate performance is improved for highly correlated signals, but power consumption increases

Engineering Contradiction:
Improvebit error rate performanceVSAvoidpower consumption
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The system dynamically adjusts power consumption by selecting the detector type based on channel correlation. The sphere detector, which consumes more power, is only activated when the correlation factor indicates it will provide meaningful BER improvement. This dynamic power management resolves the contradiction between reliability and energy usage.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the power consumption parameter by switching detector modes. When channel correlation is low, the lower-power MMSE detector is used; when correlation is high, the higher-power sphere detector is activated. This parameter adaptation resolves the energy-reliability tradeoff.

Inventive Principle:
Principle #35Parameter changes

3Use of energy by moving object

If an MMSE detector is used for signal detection, then power consumption is reduced, but bit error rate performance deteriorates for highly correlated signals

Engineering Contradiction:
Improvepower consumptionVSAvoidbit error rate performance
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The system dynamically selects the detector type based on real-time channel correlation assessment. The MMSE detector is used as the default low-power option, but the system dynamically switches to the sphere detector when correlation exceeds the threshold, ensuring BER performance is maintained when needed. This resolves the contradiction between power efficiency and reliability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system changes the detection performance parameter by adjusting detector selection based on channel conditions. The correlation factor serves as the control parameter that determines whether to use the power-efficient MMSE detector or the performance-optimized sphere detector, resolving the energy-reliability tradeoff.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS8675784B1Channel adaptive sphere detector
Publication Date: 2014.03.18 XILINX INC
  • US8675784B1 patent drawing
  • US8675784B1 patent drawing
  • US8675784B1 patent drawing

AI summary

A method for detecting communications from multiple transmission antennas includes receiving a signal with at least one receive antenna, wherein the signal comprises data transmitted from at least one of the transmission antennas, calculating an equalized received signal and an equalized channel matrix using the signal and a channel matrix, determining whether a correlation factor threshold value is exceeded, and based on the act of determining, generating a listed based log likelihood ratio (LLR) soft output or a MMSE LLR soft output based on the equalized received signal and the equalized channel matrix.