Digital Beamforming Phase Shifting With Multiplier-Less CORDIC
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Solution Overview
Problem
Conventional digital beamforming systems face inefficiencies due to the high number of multiplications required for phase shifting in phased array antennas, which increases power consumption and reduces energy efficiency, especially with large numbers of antenna elements, channels, and beams.
Innovation Solution
The implementation of multiplier-less phase shifters using Coordinate Rotation Digital Computer (CORDIC) algorithms combined with Inverse Fast Fourier Transform (IFFT) and element combiner scaling into a single scaling factor, reducing the number of multiplications needed for phase shifting in digital beamforming phased array antennas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional digital beamforming systems use traditional phase shifting methods, then phase shifting functionality is achieved, but the number of multiplications increases significantly leading to high power consumption
Solution Approach 1:
The patent transforms the phase shifting operation from traditional complex multiplication to a parameter-based approach using CORDIC algorithms. By changing the computational parameters from direct multiplication to iterative rotation operations with pre-computed angles, the system achieves phase shifting with significantly reduced multiplication operations. The phase shift is accomplished through coordinate rotation using shift-and-add operations instead of full multiplication, directly addressing the power consumption issue while maintaining functionality.
Solution Approach 2:
The patent replaces the traditional mechanical multiplication operation with an algorithmic substitution using CORDIC (Coordinate Rotation Digital Computer). Instead of using multipliers as physical computing elements, the system uses a sequence of simple shift and add operations that mimic the effect of multiplication through iterative rotation. This substitution eliminates the need for complex multiplier circuits, thereby reducing power consumption while achieving the same phase shifting effect.
2Adaptability or versatility
If the number of antenna elements, channels, and beams is increased, then system capability and coverage are improved, but power consumption increases due to more multiplications required
Solution Approach 1:
The patent implements a universal CORDIC-based phase shifting architecture that can handle any number of antenna elements, channels, and beams using the same computational approach. The multi-functionality of the CORDIC algorithm allows it to perform phase shifting for arbitrary beamforming configurations without requiring additional multiplication resources. This universal approach enables the system to scale in capability while maintaining consistent power efficiency characteristics across different system configurations.
Solution Approach 2:
The patent applies partial action by using only the necessary computational steps required for phase shifting through CORDIC iterations, rather than performing full multiplication operations. The iterative nature of CORDIC allows the system to perform just enough computational work to achieve the required phase shift accuracy, avoiding excessive calculations. This partial action approach ensures that power consumption scales gracefully with system capability increases, as only the minimal required operations are executed.
3Measurement precision
If traditional complex multiplication is used for phase shifting, then accurate phase control is achieved, but the computational complexity and power consumption increase
Solution Approach 1:
The patent segments the complex multiplication operation into multiple smaller CORDIC iteration steps. Instead of performing one large multiplication operation, the phase shifting is achieved through a sequence of smaller rotation operations, each with reduced computational complexity. This segmentation maintains phase control accuracy by accumulating small rotation angles that collectively achieve the desired total phase shift, while significantly reducing the energy required compared to a single full multiplication operation.
Solution Approach 2:
The patent introduces dynamics into the phase shifting process by using iterative CORDIC rotations that can adaptively converge to the required phase accuracy. The dynamic nature of the iterative algorithm allows the system to perform fewer iterations when lower precision is acceptable and more iterations when higher precision is needed, optimizing energy efficiency based on actual requirements. This dynamic approach replaces the static, always-maximum-precision complex multiplication with a flexible, demand-driven computational process.
Data Source
AI summary
Technologies directed to energy efficient phase shifting in digital beamforming in phased array antennas in communication systems are described. Digital signal processing (DSP) circuitry includes a first phase shifter that generates second data by phase shifting first data according to a rotation-based operation without multiplication of the second data, a second phase shifter that generates fourth data by phase shifting third data according to the rotation-based operation without multiplication of the fourth data, a combiner that generates fifth data by adding the second data and the fourth data, and a multiplier that generates sixth data by multiplying the fifth data by a constant value.