Multi-Band Radio Unit Switching for Unsynchronized TDD Timing
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Solution Overview
Problem
Current radio units face challenges in supporting un-synchronized Time Division Duplex (TDD) multi-band operation due to the need for synchronized Uplink/Downlink (UL/DL) switch timing across all frequency bands, which limits flexible radio resource management and introduces signal leakage issues when combining TDD and Frequency Division Duplex (FDD) operations.
Innovation Solution
A radio unit with parallel switch networks controlled by a switching unit to manage separate frequency bands, allowing for independent TDD time slot configurations and simultaneous TDD and FDD operations, using a shared Power Amplifier (PA) and Low Noise Amplifier (LNA) hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If one common PA is used to support multi TDD frequency bands, then hardware cost and device size are reduced, but all radio units are forced to have the same UL/DL TDD switch timing which limits radio resource management flexibility
Solution Approach 1:
The patent divides the single PA output path into multiple independent paths using separate switch networks for each frequency band. Each switch network can be controlled independently with different TDD timing, allowing one PA to support multiple bands with different UL/DL configurations. This segmentation resolves the contradiction by maintaining hardware sharing while enabling flexible independent control.
Solution Approach 2:
The patent introduces dynamic control of switch networks that can independently adjust TDD timing for each frequency band. The switch networks dynamically switch between transmitting and receiving modes based on band-specific TDD configurations, enabling adaptive radio resource management while sharing the common PA hardware.
2Device complexity
If TDD and FDD operations are combined in the same radio unit with shared hardware, then device size and cost are reduced, but transmitter signals leak into the receiver chain causing blocking or desensitization
Solution Approach 1:
The patent segments the RF path into separate transmitting and receiving paths using switch networks. When transmitting, the switch connects PA to antenna while isolating the receiver chain; when receiving, it connects antenna to receiver while isolating the PA. This segmentation prevents transmitter signals from leaking into the receiver chain while allowing TDD and FDD operations to share the same hardware.
Solution Approach 2:
The switch network acts as an intermediary between the PA and the antenna/receiver chain. It mediates the connection by selectively coupling or decoupling components based on operating mode, preventing direct signal leakage while enabling shared hardware operation for both TDD and FDD modes.
3Reliability
If separate PA and LNA hardware are used for each frequency band, then signal leakage is prevented and operation reliability is improved, but device size, weight, and cost increase
Solution Approach 1:
The patent segments the control function for each frequency band while sharing the common PA and LNA hardware. Separate switch networks provide independent control paths for each band, ensuring reliable isolated operation while avoiding the need for separate PA and LNA hardware for each band. This achieves reliability through control segmentation rather than hardware duplication.
4Ease of operation
If synchronized UL/DL switch timing is used across all frequency bands, then hardware control is simplified, but flexible radio resource management and different traffic model optimization are limited
Solution Approach 1:
The patent segments the control mechanism into separate switch networks for each frequency band, each with independent control logic. This allows synchronized hardware operation while enabling different TDD timing configurations for each band, resolving the contradiction between control simplicity and operational flexibility.
Solution Approach 2:
The switch networks provide universal control functionality that can operate in both synchronized and unsynchronized modes. The same hardware structure supports multiple operating modes, allowing flexible adaptation to different traffic models while maintaining ease of hardware control through a unified design approach.
Data Source
AI summary
A radio unit for TDD multi-band operation in a wireless communication system is disclosed. The radio unit comprises a transmitting power amplifier for multi-band operation; one or more receiving amplifiers for multi-band operation and an antenna element. The radio unit further comprises one or more switch networks coupled in parallel between the power amplifier and the antenna element. Each of the one or more switch networks comprises one or more shunt switches coupled between an output of the transmitting power amplifier and a signal ground. Each of the one or more switch networks is configured to operate at a certain frequency band in transmitting or receiving mode and is controlled separately by a switching control unit based on un-synchronized TDD time slots configured according to user data traffic scheduling requirements.