Phase Angle Mapping for RF Transmitter Encoding
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Solution Overview
Problem
Current phase modulation techniques face increased computational overhead as the number of phase differentials increases, necessitating more efficient methods to encode digital data in phase modulation schemes.
Innovation Solution
A technique that determines an angle corresponding to the arctangent of a ratio of digital data words using a memory table populated with representative angles, minimizing computational resources by approximating the arctangent function within a specified neighborhood, allowing for efficient phase modulation in RF transmitters.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the number of phase differentials is increased to represent more digital data, then the encoding capability is improved, but the computational overhead increases
Solution Approach 1:
The patent pre-calculates and stores phase angle values in a lookup table before operation. During phase modulation, the system only needs to retrieve pre-computed values based on input data patterns, avoiding real-time arctangent calculations. This preliminary preparation resolves the contradiction by shifting computational burden from operation time to setup time, enabling high encoding capability with minimal runtime computational overhead
Solution Approach 2:
The patent creates a simplified representation of phase angles by storing discrete angle values in a lookup table rather than computing continuous arctangent values. This copying approach replaces complex mathematical computation with simple table lookup operations, maintaining accurate phase differential encoding while dramatically reducing computational complexity during operation
2Productivity
If a lookup table is used to reduce computational overhead, then the processing speed is improved, but the memory requirement increases
Solution Approach 1:
The patent segments the phase angle space into discrete regions corresponding to different input data patterns. The lookup table stores only the representative phase angle for each segment rather than all possible continuous values. This segmentation approach resolves the contradiction by organizing memory storage efficiently, achieving fast processing through targeted table lookups while minimizing the total number of stored values
Solution Approach 2:
The patent changes the representation parameter from continuous arctangent values to discrete indexed values in a lookup table. By mapping input data patterns to discrete table indices rather than computing continuous angles, the system achieves fast processing through integer-based indexing while reducing memory requirements through discrete value storage instead of floating-point calculations
Data Source
AI summary
In determining an angle for a phase modulation scheme, a key is generated from a prescribed set of bits contained in a symbol. The symbols have an in-phase (I) data word and a quadrature phase (Q) data word that identify coordinates of the symbols in a complex number plane. An angle is retrieved from a memory table from a storage location identified by the key. Each angle in the memory table is established in accordance with constraints under which the memory table was populated so as to be mapped to a phase angle identifying other coordinates in the complex number plane that are within a specified neighborhood about the coordinates of each of the symbols. A signal is generated to convey the symbols as phase differentials at each sample time between a reference phase and the phase angle.