Power Amplifier Noise Compensation via TDD Receiver Path Sharing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional wireless devices face inefficiencies in implementing digital pre-distortion (DPD) filters to compensate for nonlinear power amplifier noise, requiring specialized hardware and additional computational resources and board space for feedback signal processing.
Innovation Solution
A time division duplexing (TDD) configured radio frame is used to provide both feedback signals and wireless transmission signals through a single receiver path, allowing a switch to activate a path for feedback during uplink periods and deactivate it during downlink periods, optimizing resource usage and board space.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single receiver path is used to process both feedback signals and wireless transmission signals, then device complexity and board space are reduced, but it becomes difficult to provide dedicated feedback signal processing capability
Solution Approach 1:
The patent implements time-division multiplexing where the receiver path alternates between processing feedback signals during uplink periods and processing wireless transmission signals during downlink periods. This periodic switching enables a single receiver path to handle both signal types sequentially, reducing hardware complexity while maintaining full processing capability for both signal types.
Solution Approach 2:
The receiver path is designed to perform multiple functions by processing different signal types at different times. The same receiver path that processes wireless transmission signals is also used to process feedback signals, making the hardware universal and eliminating the need for dedicated feedback processing paths.
2Measurement precision
If specialized hardware is implemented for DPD filter coefficient calculation and feedback processing, then noise compensation precision is improved, but manufacturing cost and device complexity increase
Solution Approach 1:
The patent employs a universal receiver path that handles both feedback signal processing and wireless transmission signal processing. This multi-functional approach eliminates dedicated hardware for feedback processing while maintaining the computational precision needed for DPD filter coefficient calculation through software-based processing in the coefficient calculator.
Solution Approach 2:
The patent replaces specialized hardware implementations with software-based processing in the coefficient calculator. The DPD filter coefficients are calculated using digital signal processing algorithms executed by a general-purpose processor, substituting dedicated hardware circuits with flexible software computation that achieves the same precision with reduced hardware complexity.
Data Source
AI summary
Examples described herein include methods, devices, and systems which may compensate input data for non-linear power amplifier noise to generate compensated input data. In compensating the noise, during an uplink transmission time interval (TTI), a switch path is activated to provide amplified input data to a receiver stage including a coefficient calculator. The coefficient calculator may calculate an error representative of the noise based partly on the input signal to be transmitted and a feedback signal to generate coefficient data associated with the power amplifier noise. The feedback signal is provided, after processing through the receiver, to a coefficient calculator. During an uplink TTI, the amplified input data may also be transmitted as the RF wireless transmission via an RF antenna. During a downlink TTI, the switch path may be deactivated and the receiver stage may receive an additional RF wireless transmission to be processed in the receiver stage.