Multi-Antenna Radio Transmitter DPD with Shared Observation Branch
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional digital pre-distortion (DPD) solutions face challenges in high efficiency and linearity for radio transmitters with many antennas, leading to increased complexity, power consumption, and thermal issues due to the need for multiple observation branches and actuator components.
Innovation Solution
A radio transmitter design that uses a single observation branch to determine and apply pre-distortion functions for multiple antenna ports, reducing complexity and power consumption by sharing PA parameter monitoring and using least squares, recursive least squares, or least mean square processes to minimize error in pre-distortion application.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional DPD solutions are used with multiple observation branches for each antenna port, then linearity and efficiency can be maintained, but device complexity and power consumption increase significantly
Solution Approach 1:
The patent merges the DPD functions for multiple antenna ports into a single shared observation branch. Instead of having separate observation branches for each antenna port, one DPD actuator processes signals from multiple PAs corresponding to different antenna ports. This consolidation reduces the number of observation branches and actuators while maintaining the ability to compensate for nonlinearity in each PA, thereby reducing device complexity without sacrificing linearity performance.
Solution Approach 2:
The single DPD actuator is designed to perform multiple functions by processing observation signals from multiple antenna ports. The actuator determines multiple pre-distortion functions, each corresponding to a different antenna port, and applies appropriate pre-distortion to baseband signals for different antenna ports. This multi-functional approach allows one component to replace what would traditionally require multiple separate components, reducing overall system complexity.
2Loss of energy
If conventional DPD solutions with multiple observation branches are implemented, then high efficiency can be achieved, but power consumption increases
Solution Approach 1:
By merging multiple observation branches into a single shared observation branch, the patent reduces the total number of active components that consume power. The single DPD actuator processes signals from multiple PAs, eliminating the need for multiple separate actuators and their associated power consumption. This consolidation maintains the efficiency benefits of DPD while significantly reducing the overall power consumption of the transmitter system.
3Reliability
If conventional DPD solutions with multiple observation branches are used, then linearity can be maintained, but thermal performance deteriorates
Solution Approach 1:
The patent reduces thermal performance deterioration by merging multiple observation branches and actuators into a single shared observation branch and DPD actuator. Fewer active components mean less heat generation and better thermal management. The consolidated architecture maintains the necessary linearity compensation functionality while reducing the overall thermal load on the system, leading to improved thermal performance.
4Measurement precision
If multiple observation branches and actuators are deployed for each antenna port, then pre-distortion accuracy can be maintained, but cost increases
Solution Approach 1:
The patent reduces cost by merging multiple observation branches and actuators into a single shared observation branch and DPD actuator that serves multiple antenna ports. This consolidation reduces the bill of materials, simplifies manufacturing, and lowers overall system cost. The single actuator maintains pre-distortion accuracy by determining separate pre-distortion functions for each antenna port based on the shared observation signals, ensuring that cost reduction does not come at the expense of performance.
Data Source
AI summary
A radio transmitter and a method therefor are disclosed. According to an embodiment, the radio transmitter comprises a first power amplifier (PA) corresponding to a first antenna port, an observation receiver, a first determination module, a first pre-distortion module, one or more second PA each corresponding to a second antenna port, one or more second determination module and one or more second pre-distortion module. The first determination module is configured to determine a first function reflecting a nonlinearity of the first PA, based on a first input signal to the first PA, an observation signal from the observation receiver and a first set of parameters characterizing the first PA. The first pre-distortion module is configured to determine and apply a first pre-distortion to a first baseband signal for the first antenna port. Each second determination module is configured to determine a second function reflecting a nonlinearity of the second PA, based on the first function and a difference between a second set of parameters characterizing the second PA and the first set of parameters. Each second pre-distortion module is configured to determine a second pre-distortion based on the second function and apply the second pre-distortion to a second baseband signal for the second antenna port.