Antenna Selection for Concurrent Independent Transmissions
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Solution Overview
Problem
Concurrent transmission in communication devices with multiple transmitters leads to intermodulation distortion (IMD), spurious emissions, and increased RF radiation exposure, which are managed by reducing transmit power, resulting in reduced Total Radiated Power (TRP) and throughput.
Innovation Solution
A communication device and method that optimizes antenna selection by identifying alternate antennas with lower efficiency but improved isolation, allowing for increased Total Radiated Power (TRP) while maintaining IMD within limits, by configuring the antenna switch to connect the second transmitter to the antenna with the highest available TRP.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If transmit power is reduced to manage intermodulation distortion and RF radiation exposure, then harmful factors are controlled, but Total Radiated Power and throughput decrease
Solution Approach 1:
The patent changes the parameter of antenna selection from conventional single-antenna per transmitter to multi-antenna selection with different efficiency ratings. By selecting antennas with lower efficiency ratings for certain transmitters, the system can operate at higher power levels while maintaining acceptable IMD levels, thus increasing TRP and throughput without exceeding harmful emission limits.
Solution Approach 2:
The patent applies different antenna selection criteria to different transmitters based on their specific operating conditions, frequency bands, and isolation requirements. Each transmitter is paired with an antenna that has optimized characteristics for that specific transmitter, allowing localized optimization of the TRP-IMD tradeoff for each transmit path.
2Power
If conventional antenna selection is used to maximize radiation efficiency, then TRP is increased, but intermodulation distortion products increase causing self-desensitization
Solution Approach 1:
The patent changes the selection criterion from maximizing antenna efficiency to optimizing the balance between antenna efficiency and isolation characteristics. By selecting antennas with lower efficiency but better isolation properties, the system achieves higher TRP while keeping IMD products below thresholds that cause self-desensitization.
Solution Approach 2:
The system uses feedback from measured or calculated isolation levels between antenna pairs to dynamically select the optimal antenna configuration. The controller evaluates the isolation characteristics of available antenna combinations and selects the configuration that provides sufficient isolation to prevent harmful IMD while maximizing TRP.
Data Source
AI summary
A communication device has a controller that selects one of at least two second antennas for concurrent transmission with a first antenna. The controller monitors concurrent communication activity of a first and a second transmitter. Based on the concurrent communication activity, the controller identifies respective transmit power limits associated with intermodulation distortion (IMD) for the first antenna transmitting at the first transmit frequency and one of the at least two second antennas transmitting at the second transmit frequency. The controller identifies available total radiated power (TRP), respectively, for each of the at least two second antennas and connects the second transmitter to one of the at least two second antennas having the highest available TRP to optimize communication performance.