Amplitude-Phase Symbol Modulation for Improved Spectrum Utilization
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Solution Overview
Problem
The existing wireless communication technologies using differential phase shift keying (DPSK) face challenges in improving spectrum utilization due to the single dimension of phase difference used for data transmission, which limits efficient data transmission in the presence of phase noise, frequency offset, or time offset.
Innovation Solution
A method that utilizes both amplitude and phase differences of symbols to carry data, where the amplitude of a transmission symbol is determined by M1 bits and the phase is determined by the phase of the previous symbol and M2 bits, allowing for (M1+M2)*N bits of information to be transmitted using N+1 symbols.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If only phase difference is used to carry data in differential phase modulation, then the system is simple to implement, but the spectrum utilization is low
Solution Approach 1:
The patent transitions from single-dimensional phase difference modulation to two-dimensional modulation by incorporating both amplitude and phase differences. Each symbol now carries information through both amplitude variations (M1 bits) and phase variations (M2 bits), effectively adding a dimensional layer to the modulation space and doubling the information capacity per symbol.
Solution Approach 2:
The patent changes the modulation parameters from solely phase difference to combined amplitude and phase difference. By introducing amplitude as an additional controllable parameter with M1 bits and maintaining phase difference with M2 bits, the system expands the parameter space for data encoding, achieving (M1+M2)*N bits transmission efficiency.
2Reliability
If phase difference modulation is used in presence of phase noise and frequency offset, then data transmission can be implemented, but the dimension is single and spectrum utilization needs improvement
Solution Approach 1:
The patent adds amplitude dimension to the existing phase difference modulation, creating a two-dimensional modulation scheme. This allows the system to maintain robustness against phase noise and frequency offset through phase difference while simultaneously improving spectrum utilization by encoding additional information in the amplitude dimension.
Solution Approach 2:
The patent creates a composite modulation scheme that combines amplitude shift keying and differential phase shift keying elements. This composite approach leverages the noise robustness of differential phase modulation while incorporating the high-information-density capability of amplitude modulation, achieving both reliability and efficiency.
Data Source
AI summary
A symbol transmitting method, including: determining N+1 transmission symbols s0, s1, s2, . . . , sN, according to a reference symbol and (M1+M2)*N bits, where 0, 1, 2, . . . , N are indices of the N+1 transmission symbols, s0 is a reference symbol, an amplitude of a transmission symbol with index n is determined according to M1 bits, a phase of the transmission symbol with index n is determined according to a phase of a transmission symbol with index n−1 and M2 bits, M1 is an integer greater than or equal to 1. M2 is an integer greater than or equal to 1, N is an integer greater than or equal to 1, 1≤n≤N, and n is an integer; and transmitting the N+1 transmission symbols.