Single-Carrier Constellation Estimation for Amplifier Distortion
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Solution Overview
Problem
Existing wireless communication technologies face challenges in maintaining high data rates while utilizing the non-linear region of amplifiers, leading to potential data distortion and erroneous transmission.
Innovation Solution
A wireless communication system employing a single-carrier multi-value modulation scheme that includes a transmission apparatus with a variable transmission signal amplifier, providing the reception apparatus with amplifier specifications and transmission power information, enabling signal point estimation, detection, and likelihood calculation to correct for distortion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If transmission power is increased to improve signal-to-noise ratio, then data transmission reliability is improved, but amplifier distortion increases causing erroneous transmission
Solution Approach 1:
The transmitter pre-calculates and applies non-linear compensation to the modulation signal before amplification, anticipating the amplifier's non-linear distortion. This preliminary correction ensures that even when the amplifier operates in its non-linear region with high power, the transmitted signal remains accurate, preventing erroneous transmission while maintaining high reliability
Solution Approach 2:
The system changes the parameters of the modulation signal by applying non-linear compensation that accounts for the amplifier's specific characteristics. By adjusting the signal parameters (amplitude and phase) in advance to compensate for expected non-linear distortion, the system enables high-power transmission without suffering from amplifier distortion, thus improving reliability while avoiding harmful effects
2Object-generated harmful factors
If transmission power is limited to linear region to avoid distortion, then amplifier distortion is reduced, but signal-to-noise ratio decreases reducing data transmission capability
Solution Approach 1:
The transmitter applies non-linear compensation in advance to the modulation signal, allowing the amplifier to operate at high power levels in its non-linear region while still producing accurate transmitted signals. This eliminates the need to restrict power to the linear region, thereby maintaining high signal-to-noise ratio without suffering from amplifier distortion
Solution Approach 2:
The system converts the amplifier's non-linear characteristic, which was previously a harmful factor causing distortion, into a beneficial feature. By operating in the non-linear region with high power and applying pre-compensation, the system achieves both high signal-to-noise ratio and accurate transmission, turning the amplifier's non-linearity from a problem into an enabler of high-power operation
3Measurement precision
If pilot signals are transmitted frequently to correct phase shifts, then phase shift correction accuracy is improved, but data transmission efficiency decreases
Solution Approach 1:
The system uses the actual data signal itself to estimate and correct non-linear distortion characteristics, rather than relying on separate pilot signals. The receiver estimates the non-linear characteristics by processing the received data signal, and this information is fed back to the transmitter for compensation. This self-service approach eliminates the need for frequent pilot signal transmission, maintaining high phase shift correction accuracy while preserving data transmission efficiency
Solution Approach 2:
The data signal serves multiple functions: it carries information and simultaneously provides the basis for estimating non-linear distortion characteristics. By making the data signal multi-functional, the system eliminates the need for separate pilot signals, thereby maintaining data transmission efficiency while still achieving accurate phase shift correction through the universal use of the data signal for both purposes
Data Source
AI summary
Provided is a wireless communication system using a single-carrier multi-value modulation scheme, the wireless communication system aiming at preventing erroneous transmission of data and securing a high data rate while utilizing a non-linear region of an amplifier. A reception apparatus acquires, from a transmission apparatus, a specification related to an input/output characteristic of a transmission signal amplifier and transmission power of data transmission. On the basis of the specification and the transmission power, a constellation of signal points is estimated. A reception point, which is a point in constellation coordinates, of a reception signal is detected, and likelihood calculation for the reception point is performed with respect to the signal points. A symbol intended by the reception point is identified on the basis of a result of the likelihood calculation.