RF Transmitter Dynamic Waveform Control for Power Efficiency

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Radio frequency communication systems face challenges in maintaining signal quality and power efficiency, particularly at cell edges and in harsh environments, due to high peak-to-average power ratios (PAPR) and modulation complexity, which affect data rates and battery life.

Innovation Solution

The implementation of a radio frequency communication system with dynamic waveform control and power boost, where the transmitter changes the waveform type from a high PAPR type to a lower PAPR type, such as from CP-OFDM to DFT-s-OFDM, and adjusts power based on the duty cycle and specific absorption rate (SAR) to enhance signal transmission.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high PAPR waveform types (e.g., CP-OFDM) are used for transmission, then data rate and spectral efficiency are improved, but power amplifier size and energy consumption increase

Engineering Contradiction:

Improvedata rateVSAvoidpower amplifier size

Core Design Contradiction:

ProductivityVSWeight of stationary object

Solution Approach 1:

The system dynamically switches between different waveform types (CP-OFDM and DFT-s-OFDM) based on channel conditions, user position, and quality of service requirements. This dynamic adaptation allows the system to use high PAPR waveforms only when necessary for achieving high data rates, while using low PAPR waveforms in other scenarios to reduce power amplifier size and energy consumption.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system changes the PAPR parameter by selecting different waveform types. CP-OFDM provides high spectral efficiency and data rates but has high PAPR requiring larger power amplifiers. DFT-s-OFDM has lower PAPR allowing for smaller power amplifiers. The system adjusts this parameter based on operational requirements.

Inventive Principle:

Principle #35Parameter changes

2Productivity

If high PAPR waveform types are used to increase data rate, then spectral efficiency is improved, but battery life deteriorates

Engineering Contradiction:

Improvedata rateVSAvoidbattery life

Core Design Contradiction:

ProductivityVSDuration of action of moving object

Solution Approach 1:

The system dynamically adapts waveform selection based on channel conditions and QoS requirements. By using DFT-s-OFDM in scenarios where high data rate is not critical, the system reduces power consumption and extends battery life. High PAPR waveforms are reserved for scenarios where performance requirements justify the additional energy expenditure.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The system applies high PAPR waveforms partially - only when and where needed to meet QoS requirements - rather than continuously. This selective use of high-performance waveforms optimizes the trade-off between data rate achievement and energy consumption, extending battery life while maintaining necessary performance levels.

Inventive Principle:

Principle #16Partial or excessive action

3Reliability

If power is boosted to improve signal quality at cell edges, then signal-to-noise ratio is improved, but specific absorption rate limits may be exceeded

Engineering Contradiction:

Improvesignal qualityVSAvoidspecific absorption rate

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The system changes the PAPR parameter by switching to DFT-s-OFDM waveforms, which have inherently lower peak power requirements. This allows the system to maintain signal quality at cell edges while keeping the average transmit power within SAR compliance limits, avoiding the need for excessive power boosting that would violate regulatory constraints.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The system converts the limitation of lower peak power (which would normally be seen as a disadvantage for cell edge coverage) into a benefit by using DFT-s-OFDM waveforms. These waveforms achieve acceptable signal quality at cell edges with lower average power, thereby maintaining SAR compliance while still providing reliable coverage.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

4Productivity

If modulation complexity is increased to improve data rate, then spectral efficiency is improved, but power consumption increases

Engineering Contradiction:

Improvedata rateVSAvoidpower consumption

Core Design Contradiction:

ProductivityVSUse of energy by moving object

Solution Approach 1:

The system dynamically selects modulation schemes and waveform types based on channel conditions and QoS requirements. By adapting modulation complexity to actual needs rather than using the highest complexity continuously, the system achieves necessary data rates while minimizing power consumption. Simpler modulations are used when channel conditions permit, reducing the energy burden on mobile devices.

Inventive Principle:

Principle #15Dynamics

Data Source

PatentUS11489655B2Radio frequency communication systems with dynamic waveform control and power boost

Publication Date: 2022.11.01 SKYWORKS SOLUTIONS INC

AI summary

Radio frequency (RF) communication systems with dynamic waveform control and power boost are provided herein. In certain embodiments, an RF communication system includes a power amplifier configured to amplify an RF signal to generate an RF transmit signal for transmission over a time-division duplex (TDD) communication link having a duty cycle, and a transmitter configured to provide the RF signal to the power amplifier. The transmitter is operable to change a type of waveform of the RF signal from a first waveform type to a second waveform type in response to a decrease in a signal-to-noise ratio (SNR) of the TDD communication link, and to boost a power of the RF transmit signal by an amount based on the duty cycle.