Phase Compensation in Network Access Node Transmitters

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In the 5G wireless communication system, the initial cell search process is hindered by phase shifts due to frequency offsets between the network access node and the client device, leading to increased complexity and resource consumption in phase compensation, especially in the network access node.

Innovation Solution

A processing device for network access nodes that generates phase-compensated modulation symbols by obtaining frequency and time offset parameters, allowing for phase compensation before resource element mapping in the baseband, thereby simplifying the transmitter processing and reducing computing resources.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If phase compensation is performed in the client device to correct frequency offsets, then phase accuracy is improved, but device complexity and computational resources increase

Engineering Contradiction:

Improvephase accuracyVSAvoidclient device complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent inverts the conventional approach by performing phase compensation in the network access node (transmitter) rather than in the client device (receiver). The processing device generates phase compensated modulation symbols by applying frequency and time offset parameters to pre-compensate the phase shifts, thereby eliminating the need for complex phase compensation processing in the client device while maintaining phase accuracy

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent applies preliminary action by performing phase compensation before resource element mapping in the baseband processing stage. The frequency and time offset parameters are obtained and applied in advance to the modulation symbols, so that when the signal is transmitted and received, the phase compensation has already been applied, simplifying the client device operations

Inventive Principle:

Principle #10Preliminary action

2Measurement precision

If phase compensation processing is performed in the network access node, then phase alignment is improved, but computational complexity increases

Engineering Contradiction:

Improvephase alignmentVSAvoidnetwork access node complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent uses parameter changes by obtaining frequency offset and time offset parameters that characterize the phase shift conditions. These parameters are then applied to generate phase compensated modulation symbols. By changing the parameters of the modulation symbols based on the offset values, the system achieves phase alignment while managing computational complexity through parameter-based processing

Inventive Principle:

Principle #35Parameter changes

3Adaptability or versatility

If frequency offset between network access node and client device is allowed, then system flexibility is improved, but phase shift accuracy deteriorates

Engineering Contradiction:

Improvesystem flexibilityVSAvoidphase shift accuracy

Core Design Contradiction:

Adaptability or versatilityVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by pre-compensating the modulation symbols with frequency and time offset parameters before transmission. This allows the system to accommodate frequency offsets between network access node and client device while maintaining phase shift accuracy through advance correction

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Instead of correcting phase shifts after reception, the patent inverts the approach by pre-applying the opposite phase compensation in the transmitter. This allows frequency offset to exist for system flexibility while the phase accuracy is maintained through the inverted compensation approach

Inventive Principle:

Principle #13The other way round (Inversion)

Data Source

PatentUS11695606B2Processing device for a network access node for generating phase compensated modulation symbols

Publication Date: 2023.07.04 HUAWEI TECH CO LTD

AI summary

The disclosure relates to performing phase compensation at a transmitter. A processing device for a network access node generates a phase compensated modulation symbol based on at least one first modulation symbol and at least on one of a frequency offset parameter and a time offset parameter. The frequency offset parameter may be determined based on an offset between a reference frequency f0 and a DC (0 Hz) frequency such that the frequency offset parameter corresponds to the reference frequency f0. Also, the reference frequency f0 can be at least partly based on the carrier of up-conversion frequency used by the processing device and the reference frequency f0 can be the carrier for up-conversion frequency. The phase compensated symbol is transmitted to a receiver, such as a client device. Furthermore, the disclosure also relates to corresponding methods and a computer program.