Complex Signal Correlator Using Shifter and Adder
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Solution Overview
Problem
Existing communication systems face challenges in efficiently correlating complex signals due to the high complexity and cost of hardware implementation, particularly in performing complex multiplications required for synchronization and channel estimation.
Innovation Solution
A method and apparatus that adjust the amplitude and radial angle of received symbols based on local reference symbols, using shifters and adders instead of complex multipliers, allowing for correlation of complex signals with arbitrary amplitude and radial angle, and enabling the calculation of a local reference signal from a known signal, reducing computing load and chip size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If complex multiplication is used for signal correlation, then correlation accuracy is maintained, but hardware area and current consumption increase significantly
Solution Approach 1:
The patent transforms the complex multiplication operation into equivalent real-number operations by changing the mathematical parameters. Specifically, it uses the property that complex multiplication (a+jb)(c+jd) can be computed as (ac-bd)+j(ad+bc), where the real and imaginary parts are computed using only real multiplications and additions. This parameter transformation allows replacing complex multipliers with simpler real multipliers and adders, reducing hardware area while maintaining correlation accuracy
Solution Approach 2:
The patent substitutes the mechanical/computational complex multiplication system with a simplified system using only real multiplications and additions. By replacing the complex number arithmetic mechanism with real-number arithmetic mechanisms, the hardware implementation becomes less complex, requiring fewer transistors and less area, while achieving the same correlation function
2Measurement precision
If complex multiplication is used for signal correlation, then correlation accuracy is maintained, but current consumption increases
Solution Approach 1:
The patent changes the computational parameters from complex arithmetic to real arithmetic, which reduces the number of active transistors and logic gates required. This parameter change directly reduces dynamic power consumption since fewer switching elements are active during each correlation computation cycle
Solution Approach 2:
The patent replaces the energy-intensive complex multiplication mechanism with a lower-power real multiplication and addition mechanism. The substitution eliminates the need for complex number handling circuitry, reducing overall current consumption while preserving the essential correlation functionality
3Adaptability or versatility
If complex multiplication is used for signal correlation, then correlation functionality is complete, but chip cost increases
Solution Approach 1:
The patent changes the implementation parameters from complex arithmetic to real arithmetic, which simplifies the manufacturing process. The reduced complexity allows for smaller transistor sizes, lower process node requirements, and simpler layout designs, all of which reduce fabrication costs while maintaining correlation functionality
Solution Approach 2:
The patent substitutes complex multiplication hardware with simpler real arithmetic hardware, making the chip easier to manufacture. The simplified logic requires less precise manufacturing tolerances and can be produced using less advanced (and therefore cheaper) fabrication processes, directly reducing chip cost
4Adaptability or versatility
If arbitrary complex signals are correlated, then signal processing versatility is improved, but operation complexity increases
Solution Approach 1:
The patent changes the operational parameters by decomposing complex signal correlation into real and imaginary component operations. This parameter decomposition allows arbitrary complex signals to be processed using systematic real-number operations, reducing operational complexity through structured computation while maintaining full signal processing versatility
Solution Approach 2:
The patent segments the complex correlation operation into separate real and imaginary component calculations. By dividing the complex arithmetic into discrete real-number operations (real part calculation and imaginary part calculation), the overall operation complexity is reduced while handling arbitrary complex signals
Data Source
AI summary
In order to reduce the complexity of complex signal correlator and realize algorithm optimization, the present invention provides a method and an apparatus for implement complex signal correlation by means of shifter and adder instead of complex multiplier. In the method, the amplitude and radial angle of a corresponding received symbol is firstly adjusted based on a pre-stored local reference symbol. Then, the radial angle of the adjusted received signal is rotated based on a corresponding interchange indicator. Finally, all the processed received signals are combined to obtain a final complex correlation signal. With this method, the chip size and computing load can be greatly reduced.