Base Station Timing Adjustment for Inter-Channel Interference

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Solution Overview

Problem

In wireless communication systems using a time division duplex scheme, inter-channel interference occurs due to differences in communication distances between base stations and terminal stations, leading to increased guard times and reduced frequency utilization efficiency.

Innovation Solution

The system adjusts the transmission timing of downlink signals from base stations based on communication distances to ensure that reception timings of downlink signals in terminal stations fall within a predetermined range, thereby minimizing inter-channel interference and shortening the guard time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If transmission timings are synchronized with high accuracy among base stations, then synchronization precision is improved, but when communication distance difference is large, reception timing shift in terminal stations increases causing inter-channel interference

Engineering Contradiction:

Improvesynchronization precisionVSAvoidinter-channel interference

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by adjusting transmission timing individually for each base station based on its specific communication distance to terminal stations. Instead of uniform synchronization, each base station receives timing adjustment information tailored to its location, ensuring that downlink signal reception timings at terminal stations fall within a predetermined range regardless of communication distance variations.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the transmission timing parameter of downlink signals based on communication distance. The management station calculates timing adjustment values according to the difference in communication distances and instructs base stations to adjust their transmission timings accordingly, thereby compensating for distance-induced reception timing shifts and preventing inter-channel interference.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If guard time is increased to avoid interference, then reliability is improved, but frequency utilization efficiency deteriorates

Engineering Contradiction:

Improveinterference avoidanceVSAvoidfrequency utilization efficiency

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent optimizes the guard time parameter by adjusting transmission timings rather than simply increasing guard time duration. By changing the transmission timing parameter of downlink signals based on communication distance, the system achieves interference avoidance with a minimized guard time, thereby improving frequency utilization efficiency while maintaining reliability.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent introduces dynamic timing adjustment where guard time is optimized adaptively based on communication distance variations. Instead of using a fixed large guard time for all scenarios, the system dynamically adjusts transmission timings to achieve the minimum necessary guard time for each specific configuration, balancing reliability and productivity.

Inventive Principle:

Principle #15Dynamics

3Area of stationary object

If communication distance difference is large, then coverage area is improved, but reception timing shift increases causing inter-channel interference

Engineering Contradiction:

Improvecoverage areaVSAvoidinter-channel interference

Core Design Contradiction:

Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by providing individualized timing adjustment to each base station based on its specific communication distance characteristics. This allows the system to maintain accurate reception timing at terminal stations even when coverage area is extended through large communication distance differences, as each base station's transmission timing is locally optimized for its distance to terminal stations.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent changes the transmission timing parameter proportionally to communication distance. The management station calculates timing adjustment values based on the difference in communication distances and instructs base stations to adjust their transmission timings, thereby compensating for the reception timing shifts caused by large coverage areas and preventing inter-channel interference.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS11979898B2Wireless communication system, wireless communication method, management station device, base station device, and terminal station device

Publication Date: 2024.05.07 NIPPON TELEGRAPH & TELEPHONE CORP

AI summary

A wireless communication system includes a plurality of sets of base station devices and terminal station devices configured to perform communications in an equal frame length using a time division duplex scheme, the communications of the plurality of sets being simultaneously operated in adjacent areas, in which each of the base station devices includes a control unit configured to control a transmission timing of a downlink signal transmitted from the base station device itself based on a communication distance between the base station device and the terminal station device of each of the sets or a reception timing of a downlink signal in the terminal station device such that reception timings of downlink signals transmitted from the base station device itself and other base station devices in the terminal station devices of the sets fall within a predetermined range determined in advance.