PN Code Phase Shifting Using LFSR Transition Matrices
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Solution Overview
Problem
Conventional signal processing devices face inefficiency in generating phase-shifted PN code sequences, requiring numerous clock cycles, which leads to time wastage and inefficiency during data transmission synchronization.
Innovation Solution
The proposed solution involves generating a fundamental matrix based on the LFSR circuit's structure and using matrix operations to directly derive phase-shifted PN code sequences, eliminating the need for sequential clock cycle shifts by multiplying the input sequence with the fundamental matrix raised to the power of the required phase shift.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If sequential shifting of LFSR values is used to generate phase-shifted PN code sequences, then the generation process follows the conventional sequential clock cycle mechanism, but the time required increases significantly when the phase shift amount k is large
Solution Approach 1:
The patent replaces the mechanical sequential clock cycle-based LFSR shifting mechanism with a mathematical matrix operation system. By representing the LFSR state transitions as matrix multiplications, the system can compute phase-shifted sequences through direct matrix operations rather than sequential clock cycles, dramatically reducing the time required for large phase shifts.
Solution Approach 2:
The patent changes the fundamental parameter of sequence generation from time-based sequential shifting to matrix-based direct computation. By pre-calculating and storing phase-shifted versions of the PN code sequence as matrices, the system can instantly retrieve any phase-shifted sequence by selecting the appropriate matrix, eliminating the time penalty associated with large phase shift values k.
2Reliability
If the LFSR circuit sequentially shifts values for k clock cycles to achieve phase shift, then the phase-shifted version is obtained through step-by-step progression, but this causes waste of time and efficiency problems
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing multiple phase-shifted versions of the PN code sequence as matrices before they are needed. These pre-computed matrices represent sequences shifted by different amounts (e.g., 1 cycle, 2 cycles, ..., N cycles), allowing the receiver to instantly access the required phase-shifted sequence without performing real-time sequential shifting.
Solution Approach 2:
The patent creates multiple copies of the PN code sequence, each copy being phase-shifted by a different amount and stored as a separate matrix. Instead of generating one sequence and shifting it sequentially, the system maintains parallel copies of the sequence at different phase positions, enabling immediate retrieval of any required phase shift without time-consuming sequential operations.
Data Source
AI summary
A signal processing method performed by a processor of a signal processing device and includes: generating a fundamental matrix according to at least one set of fundamental coefficients; generating a phase-shifted matrix according to a predetermined phase shift and the fundamental matrix; and generating an output sequence according to an input sequence and the phase-shifted matrix. The set of fundamental coefficients is used to generate at least one bit of a code sequence, the output sequence is a phase-shifted version of the input sequence being shifted by k cycle(s), and k is the predetermined phase shift.