Multi-Transceiver RF Processing With Wideband DPD Across Adjacent Blocks
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Solution Overview
Problem
Current transmitters with integrated DPD cores in Field Programmable Gate Arrays (FPGAs) are unable to fulfill the high bandwidth needs of 3GPP 5G technology standards, particularly in supporting wide frequency bands like 3GPP B42 and B43 in Europe, and CBRS C-band in the United States, due to inefficiencies in implementing Digital Pre-distortion (DPD) for linear operation.
Innovation Solution
A multi-transceiver radio frequency (RF) signal processing system with a controller, DPD core, and transceiver paths that process adjacent frequency blocks in parallel, applying digital pre-distortion to minimize distortion across a wide contiguous spectrum, and utilize flexible bandwidth settings and calibration techniques to align phase and amplitude at border frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If current transmitters with integrated DPD cores in FPGAs are used, then device complexity is reduced, but bandwidth capability is insufficient to support wide frequency bands
Solution Approach 1:
The transmitter is divided into multiple independent transceiver paths, each capable of processing a portion of the total bandwidth. This segmentation allows the system to support wide frequency bands by distributing the processing load across multiple parallel paths, thereby increasing bandwidth capability while managing device complexity through modular architecture
Solution Approach 2:
Each transceiver path is designed with universal functionality to handle multiple frequency blocks. The transceiver paths can be dynamically configured and combined to support different bandwidth requirements, making the system adaptable to various wideband scenarios without requiring completely separate hardware for each frequency block
2Adaptability or versatility
If multiple transceiver paths process adjacent frequency blocks in parallel, then bandwidth capability is improved, but distortion at border frequencies increases
Solution Approach 1:
Digital pre-distortion is applied to the signal before transmission through each transceiver path. This preliminary action compensates for anticipated nonlinearities and distortion, particularly at border frequencies where adjacent frequency blocks meet, thereby reducing the harmful effects of distortion while maintaining the benefits of parallel processing
Solution Approach 2:
The system incorporates feedback mechanisms to monitor and adjust the distortion characteristics at border frequencies. By continuously measuring the actual distortion and adjusting the pre-distortion parameters accordingly, the system minimizes harmful effects while maintaining wideband operation
3Reliability
If digital pre-distortion is applied across wide frequency bands, then linearity is improved, but device complexity increases
Solution Approach 1:
The digital pre-distortion function is segmented and distributed across multiple transceiver paths rather than implemented as a single complex unit. Each path applies pre-distortion to its assigned frequency block, reducing the complexity of individual DPD implementations while collectively achieving linearity across the entire wide frequency band
Solution Approach 2:
The system dynamically adjusts the pre-distortion parameters for each transceiver path based on the specific characteristics of its assigned frequency block. This parameter adaptation allows each path to optimize linearity for its local frequency range, achieving overall wideband linearity without requiring a single overly complex pre-distortion system
Data Source
AI summary
In one embodiment, a multi-transceiver RF signal processing system comprises: a controller; a DPD core and CFR engine; and a plurality of transceiver paths comprising at least a first transceiver path for a first frequency block, and a second transceiver path for a second frequency block. The first frequency block is adjacent to the second frequency block. Signal processing outputs a stream of digital RF based on wireless RF signals received into the first and second transceiver paths. Signal processing inputs a first stream of digital RF and outputs a first digital RF signal corresponding to the first frequency block to the first transceiver path, and outputs a second digital RF signal corresponding to the second frequency block to the second transceiver path for wireless transmission via the at least one antenna. The DPD core applies a distortion that covers the first and second frequency blocks.