Reception Apparatus Channel Estimation Control Method

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing wireless communication systems face complexity and inefficiency in channel estimation due to the need for dual detection units and simultaneous calculation of reference signals in both halves of a slot, leading to increased delay and error rates in CQI channel estimation.

Innovation Solution

A receiving apparatus that selectively uses either both uplink reference signals or only the first uplink reference signal for channel estimation based on the RSSI level compared to a detection threshold value, calculated from noise power, to optimize CQI demodulation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If both DM-RS in the first half and latter half of the slot are used for channel estimation, then channel estimation accuracy is improved, but processing delay and error rates increase

Engineering Contradiction:
Improvechannel estimation accuracyVSAvoidprocessing delay
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements dynamic selection of reference signals for channel estimation based on A/N signal detection results. When A/N signal is successfully detected, only the first DM-RS is used for channel estimation; when detection fails, both DM-RS instances are used. This dynamic adaptation resolves the contradiction by adjusting the estimation process based on actual signal conditions, reducing unnecessary processing delay while maintaining accuracy when needed.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of reference signal usage from fixed (always using both DM-RS) to variable based on detection outcomes. By modifying the channel estimation process parameter (number of reference signals used) according to A/N detection success, the system optimizes the balance between estimation accuracy and processing efficiency, directly addressing the time-accuracy tradeoff.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If dual detection units with different criteria are implemented, then A/N signal detection reliability is improved, but device complexity increases

Engineering Contradiction:
ImproveA/N signal detection reliabilityVSAvoiddetection unit complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and utilizes the A/N signal detection result as a control parameter for subsequent channel estimation. Instead of implementing complex dual detection units, the system takes out the detection outcome and uses it to select the appropriate reference signal processing path, thereby achieving reliable detection without increasing device complexity through additional detection units.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The A/N detection result serves as an intermediary that mediates between the detection process and channel estimation. This intermediary signal controls which reference signals are used for estimation, creating a simple yet effective mechanism that improves reliability without requiring multiple complex detection units with different criteria.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If channel estimation is performed using both reference signals, then estimation accuracy is improved, but calculation complexity increases

Engineering Contradiction:
ImproveCQI channel estimation accuracyVSAvoidcalculation complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent applies dynamic control to the channel estimation process by making it conditional on A/N detection results. The system dynamically adjusts the estimation complexity - using simple single-reference-signal estimation when A/N is detected, and more complex dual-reference-signal estimation only when necessary. This resolves the contradiction by adapting calculation complexity to actual operational needs rather than always using the most accurate but complex method.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP2975896B1Reception apparatus in wireless communication system and channel estimation control method
Publication Date: 2019.10.09 NEC CORP
  • EP2975896B1 patent drawingFigure 1
  • EP2975896B1 patent drawingFigure 2
  • EP2975896B1 patent drawingFigure 3

AI summary

[Object] To provide a receiving apparatus in a wireless communication system and a channel estimation control method that are capable of reducing delay in channel estimation and the error rate in decoding channel information. [Solving Means] In a wireless communication system using a first reference signal, with which a control information signal is not multiplexed, and a second reference signal, with which a control information signal is multiplexed, a receiver (200) includes: an A/N detection selection unit (211) that selects whether to use both the first reference signal and the second reference signal for channel estimation or to use only the first reference signal for channel estimation; and a channel estimation unit (209) that carries out channel estimation by use of the selected reference signal(s).