Interference Adaptive Wideband Receiver IF Frequency Control

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Solution Overview

Problem

Existing wideband receivers face challenges in managing increasing bandwidth demands and complex electromagnetic environments, leading to high requirements for dynamic range and rejection performance, particularly in Multi-Stand Receivers, which results in expensive and bulky components.

Innovation Solution

A wideband receiver with an Intermediate Frequency (IF) frequency control module that detects interference conditions and dynamically selects an IF frequency to avoid interference mixed products and ADC harmonic products, using a Look-Up Table to optimize the IF frequency and mixer injection mode for different interference scenarios.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the transmission bandwidth is increased to satisfy higher data rate requirements, then the data rate is improved, but the selectivity requirement and component complexity increase dramatically

Engineering Contradiction:
Improvedata rateVSAvoidreceiver complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic IF frequency selection by detecting interference conditions and automatically adjusting the IF frequency accordingly. This dynamic adaptation allows the receiver to maintain high selectivity (e.g., 84 dB for in-band blocking, 150 dB for out-band blocking) without requiring fixed high-performance filters, thereby reducing overall receiver complexity while supporting wideband operation for high data rates

Inventive Principle:
Principle #15Dynamics

2Reliability

If the dynamic range and rejection performance requirements are increased to handle complex electromagnetic environments, then the blocking performance is improved, but the cost and size of components increase

Engineering Contradiction:
Improveblocking performanceVSAvoidcomponent specifications
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the operating parameter (IF frequency) dynamically based on detected interference conditions. By selecting different IF frequencies (e.g., avoiding frequencies that would create high mixed products with blocking signals), the system achieves high blocking performance without requiring components with extremely high static specifications, thereby reducing cost and size

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the potentially harmful effect of blocking signals into a manageable problem by detecting the interference conditions and using this information to select IF frequencies that avoid creating high mixed products. This approach transforms the challenge of complex electromagnetic environments into an opportunity for adaptive optimization, maintaining reliability without excessive component specifications

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach optimizes receiver performance by reducing the requirements for components like the mixer and ADC, lowering costs and size, while maintaining effective interference suppression without significant performance deterioration.

Implementation Method 1

The frequency synthesizer is adapted to generate an oscillator signal of the selected IF frequency

Methodology Applied
Scientific EffectFrequency synthesis:

Implementation Method 2

A mixer 140 multiplies the RF signal by an oscillator signal of an Intermediate Frequency (IF) frequency generated by a frequency synthesizer 150 to down-convert the RF signal to an IF signal

Methodology Applied
Scientific EffectMixing: Heterodyne

Implementation Method 3

The IF signal then passes a Band Pass Filter (BPF) 160 such as an IF saw filter, an image filter and an Anti-alias (AA) filter

Methodology Applied
Scientific EffectFiltering: Filter (electronic)

Implementation Method 4

an antenna Filter Unit (FU) 120 which filters out outband blocking signal from the received RF signal and a Low-Noise Amplifier (LNA) 130 which amplifies the RF signal with a low Noise Figure (NF)

Methodology Applied
Scientific EffectAmplification:

Implementation Method 5

Finally an Analog-to-Digital Converter (ADC) 180 converts the IF signal to baseband data for further processing

Methodology Applied
Scientific EffectAnalog-to-digital conversion:

Data Source

PatentUS9379748B2Interference adaptive wideband receiver
Publication Date: 2016.06.28 TELEFONAKTIEBOLAGET LM ERICSSON (PUBL)

AI summary

The invention discloses a wideband receiver and a base station in a communication network. The wideband receiver comprises an Intermediate Frequency (IF) frequency control module, a frequency synthesizer, a mixer and an analog-to-digital converter (ADC). The IF frequency control module comprises an interference detector adapted to detect interference condition on at least one frequency band, and an IF frequency selector adapted to select an IF frequency based on the detected interference condition from the interference detector. The IF frequency is selected to avoid high interference mixed product of the mixer occurring in used channel. The frequency synthesizer generates an oscillator signal of the selected IF frequency, the mixer down converts a RF signal to an IF signal using the oscillator signal of the selected IF frequency, and the ADC converts the IF signal to baseband data.