Adaptive IF Wireless Receiver for Bluetooth Frequency Offset Compensation
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Solution Overview
Problem
Low IF wireless receivers face performance degradation due to fixed intermediate frequency, increased power consumption, and limitations in employing advanced algorithms like smart AFH and TX DC offset self-calibration, especially when there are local RF frequency offsets between transmitter and receiver paths.
Innovation Solution
An adaptive/configurable IF wireless receiver design featuring a low noise amplifier, adjustable RF and digital local IF synthesizers, and an IF configuration unit that allows variable frequency settings for the local RF and digital local IF clock signals, enabling flexible operation and optimizing performance by minimizing IF signal power consumption and compensating for frequency offsets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the IF is selected to be at least 1.5 times of the channel bandwidth to alleviate DC offset and flicker noise impairments, then the receiver performance is improved, but the power consumption increases
Solution Approach 1:
The patent implements dynamic IF adjustment by configuring the local RF synthesizer and digital local IF synthesizer to vary the frequency of clock signals. The IF configuration unit dynamically sets the IF frequency based on system conditions, allowing the receiver to adapt between high IF modes (for better performance) and low IF modes (for lower power consumption), resolving the contradiction between receiver performance and power consumption.
2Ease of manufacture
If the IF is fixed in the receiver design, then the implementation is simple, but the receiver suffers performance degradation when there is local RF frequency offset between TX and RX paths
Solution Approach 1:
The patent transitions from a fixed IF architecture to a dynamic IF architecture where the IF frequency can be adjusted based on detected frequency offsets. The IF configuration unit modifies the local RF and digital local IF synthesizer frequencies to compensate for frequency mismatches between transmitter and receiver paths, thereby maintaining receiver performance while adding adaptability.
Solution Approach 2:
The patent employs feedback mechanisms where frequency offset detection information is fed back to the IF configuration unit, which then adjusts the synthesizer frequencies accordingly. This closed-loop feedback system enables the receiver to automatically compensate for frequency offsets and maintain optimal performance without complex manual configuration.
3Device complexity
If the IF is fixed, then the device complexity is low, but the receiver cannot employ advanced system level algorithms like smart AFH and TX DC offset self calibration
Solution Approach 1:
The patent implements dynamic IF adjustment capability that enables the receiver to support advanced algorithms such as smart AFH and TX DC offset self calibration. The IF configuration unit can adapt the IF frequency based on algorithm requirements, allowing the receiver to employ sophisticated signal processing techniques while maintaining manageable device complexity through modular synthesis architecture.
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
The adaptive IF wireless receiver achieves reduced power consumption and improved performance by dynamically adjusting the IF signal frequency, enabling effective compensation for frequency offsets and supporting advanced algorithms, thus enhancing the receiver's flexibility and efficiency.
Implementation Method 1
a low noise amplifier configured to amplify an input RF signal
Implementation Method 2
a RF mixer configured to down convert the amplified RF signal to an analog IF signal by mixing the local RF clock signal with the amplified RF signal
Implementation Method 3
a filter configured to filter the analog IF signal
Implementation Method 4
an analog to digital converter configured to convert the filtered analog IF signal to a digital IF signal
Implementation Method 5
a digital mixer configured to down convert the digital IF signal to a baseband signal by mixing the digital local IF clock signal with the digital IF signal
Data Source
AI summary
Techniques pertaining to an adaptive/configurable IF wireless receiver are disclosed. Such an adaptive/configurable IF wireless receiver can be used in a Bluetooth device. According to one embodiment of the present invention, a wireless receiver is designed to include a low noise amplifier configured to amplify an input RF signal; an adjustable local RF synthesizer configured to provide a local RF clock signal with variable frequency; a RF mixer configured to down convert the amplified RF signal to an analog IF signal by mixing the local RF clock signal with the amplified RF signal; a filter configured to filter the analog IF signal; an analog to digital converter configured to convert the filtered analog IF signal to a digital IF signal; an adjustable digital local IF synthesizer configured to provide a digital local IF clock signal with variable frequency; a digital mixer configured to down convert the digital IF signal to a baseband signal by mixing the digital local IF clock signal with the digital IF signal; and an IF configuration unit provided to configure the adjustable local RF synthesizer to vary the frequency of the local RF clock signal, and configure the adjustable digital local IF synthesizer to vary the frequency of the digital local IF clock signal.