Satellite Transmitter Phase Control for Lower PAPR Relay Links
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Solution Overview
Problem
Existing satellite relay devices face limitations in transmission power due to high peak-to-average power ratio (PAPR) in multicarrier transmission, requiring large backoff margins in amplifiers and necessitating phase control information sharing between transmitter and receiver sides.
Innovation Solution
A satellite transmitter system with K transmission antenna elements, a multiplexing unit, digital-to-analog converter, storage for excitation coefficients, PAPR calculation, beam-to-beam relative phase calculation, and excitation coefficient calculation units, which calculate and update excitation coefficients to suppress peak power without sharing phase control information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a relay satellite communication system using frequency modulation is used, then communication stability is improved, but the bandwidth required for signal transmission increases significantly
Solution Approach 1:
The patent replaces frequency modulation (FM) with phase modulation (PM) in the satellite communication system. This substitution changes the modulation mechanism from frequency-based to phase-based signal encoding, which achieves similar communication stability while significantly reducing the bandwidth requirement. The phase modulation technique allows for more efficient spectral utilization without compromising the reliability of the communication link.
2Reliability
If the antenna gain is increased to improve communication quality, then signal reception is improved, but the antenna size and weight increase
Solution Approach 1:
The patent changes the modulation parameter from frequency modulation to phase modulation, which improves signal reception quality without requiring increased antenna gain. This parameter change allows the system to achieve better communication reliability through more efficient signal encoding rather than through hardware scaling, thereby avoiding the weight penalty associated with larger antennas.
3Device complexity
If conventional modulation techniques are used in satellite communication, then system complexity is reduced, but power consumption increases and communication efficiency decreases
Solution Approach 1:
The patent substitutes phase modulation for conventional frequency modulation in the satellite communication system. This replacement achieves lower power consumption and improved communication efficiency while maintaining manageable system complexity. The phase modulation technique requires less power for signal transmission and enables more efficient use of the available bandwidth, addressing the energy efficiency concerns without significantly complicating the system architecture.
Data Source
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AI summary
A satellite transmitter includes K transmission antenna elements, a multiplexing unit configured to multiplex each of K digital signals on a frequency axis and then convert the multiplexed digital signals to time-domain digital signals, a digital-to-analog converter, a PAPR calculation unit configured to calculate a PAPR for each of the K digital signals, a beam-to-beam relative phase calculation unit configured to calculate a beam-to-beam relative phase for suppressing a peak power of the transmission antenna elements, an excitation coefficient calculation unit configured to calculate K updated excitation coefficients based on the beam-to-beam relative phase and the beam-formation excitation coefficient, and an excitation coefficient multiplication unit configured to generate the digital signals of a frequency domain to be output to the multiplexing unit by multiplying a received relay signal by each of the K updated excitation coefficients in the frequency domain.