Digital Receiver Gain Control for Wide-Range PDSCH Demodulation

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Solution Overview

Problem

Existing automatic gain control methods in radio receiver systems, particularly in 5G OFDM terminal receivers using 256QAM modulation, struggle with accurately demodulating signals with wide energy ranges due to interference and multi-path effects, leading to demodulation failures.

Innovation Solution

A gain adjustment control method that calculates the energy of a full-bandwidth PDSCH transmission signal in the intermediate frequency or baseband digital domain, determines gain control adjustment parameters, and adjusts the receiver gain accordingly, thereby improving anti-interference performance and reducing multi-path influence.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If analog signal processing is used for automatic gain control in the RF link, then the receiver can adjust gain according to signal strength, but the system becomes susceptible to interference and multi-path effects leading to demodulation failure

Engineering Contradiction:

Improvesignal demodulation accuracyVSAvoidinterference and multi-path effects

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces the mechanical/analog gain control system in the RF link with a digital signal processing system. Specifically, it uses digital down-conversion to transform the RF signal to baseband, then applies digital automatic gain control algorithms to calculate and adjust gain based on signal energy detection in the digital domain, thereby eliminating the susceptibility to interference and multi-path effects that plague analog systems

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent introduces digital signal processing as an intermediary between the RF signal reception and the final demodulation process. By inserting a digital down-conversion stage and digital gain control mechanism, the system can process signals with wide energy ranges (greater than 10 dB) without direct analog manipulation, thus avoiding the harmful effects of analog processing on high-order modulation signals

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If constant gain is used in the receiver, then the system structure is simple, but the receiver cannot correctly demodulate signals with wide energy range

Engineering Contradiction:

Improvereceiver structureVSAvoidsignal demodulation accuracy

Core Design Contradiction:

Device complexityVSReliability

Solution Approach 1:

The patent implements dynamic gain adjustment through digital signal processing. The system continuously monitors the energy of the down-converted signal and dynamically adjusts the gain parameter based on the detected signal strength, enabling the receiver to adapt to signals with energy ranges greater than 10 dB while maintaining a relatively simple overall architecture

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS12245170B2Gain adjustment control method, device and apparatus, and computer readable storage medium

Publication Date: 2025.03.04 ZTE CORP

AI summary

A gain adjustment control method, device and apparatus, and a non-transitory computer-readable storage medium are disclosed. The method may include: calculating energy of a full-bandwidth physical downlink shared channel (PDSCH) transmission signal in an intermediate frequency digital domain or a baseband digital domain according to a set calculation period; determining a gain control adjustment parameter according to the calculated energy of the full-bandwidth PDSCH transmission signal; and controlling and adjusting a gain of a receiver according to the determined gain control adjustment parameter and a gain adjustment rule.