Discrete-Value Programmable Amplifier for Low-Power CDMA Transmitters
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Solution Overview
Problem
Current mobile radio transmitters designed for continuous time-domain data transmission face challenges with high power consumption, susceptibility to interference, and increased costs due to the use of continuous-value analog signals for automatic gain control in CDMA systems, particularly in UMTS standards.
Innovation Solution
A transmission arrangement using discrete-value control signals to actuate programmable amplifiers in both baseband and radio frequency paths, eliminating the need for digital/analog converters and providing improved power efficiency, reduced chip surface requirements, and enhanced interference robustness, while maintaining stringent error vector and spectral compliance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If continuous-value analog signals are used for automatic gain control in CDMA transmitters, then precise transmission power control is achieved, but power consumption increases and susceptibility to interference rises
Solution Approach 1:
The patent replaces the analog control system with a digital control system. Specifically, digital gain control signals are used to control programmable amplifiers in both the baseband and radio frequency paths, substituting the continuous-value analog control mechanism with a discrete digital control mechanism. This substitution maintains precise power control through digital signal processing while eliminating the need for digital-to-analog converters, thereby reducing power consumption and improving interference robustness.
2Adaptability or versatility
If continuous-value analog signals are used for automatic gain control, then transmission power can be continuously adjusted, but device complexity and production costs increase
Solution Approach 1:
The patent segments the gain control function into two distinct programmable amplifiers: one in the baseband signal processing unit and another in the radio frequency path. Each amplifier handles a portion of the overall gain adjustment, allowing the system to achieve wide dynamic range control through coordinated digital control of multiple discrete components rather than requiring a single complex analog control system.
3Ease of operation
If digital/analog converters are used for gain control signal conversion, then analog control signals are generated, but chip surface area and production costs increase
Solution Approach 1:
The patent extracts and eliminates the digital-to-analog converter from the control signal path. By implementing fully digital gain control signals that directly control programmable amplifiers, the system removes the D/A conversion stage entirely. This extraction eliminates the associated chip surface area requirements and production complexities while maintaining full control functionality through digital means.
Data Source
AI summary
A transmission arrangement is provided for transmitting data continuously in the time domain. The arrangement includes at least one programmable amplifier in the baseband or in the radio frequency path in the signal processing chain for the signal which is to be transmitted. This programmable amplifier is distinguished in that the signal which actuates the programmable amplifier is a discrete-value signal. By dispensing with complex digital/analog converters, the principle described allows markedly reduced power consumption in transmitters which use code multiple access methods.