PN Sequence Correlation Circuit With Reduced Memory Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In communication systems, computing the correlation between a received signal and a PN sequence is computationally intensive and memory-access-heavy, leading to increased costs and reduced operational efficiency due to the need for extensive calculations and continuous memory access.
Innovation Solution
A method and circuit that reduce the number of operations and memory accesses by using a control unit, storage unit, and operational unit to process PN sequences with alternating values, allowing for the computation of correlation values without full multiplication and accumulation, thereby minimizing circuit area and enhancing operational speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If linear or circular correlation is used to compute correlation between received signal and PN sequence, then synchronization and channel estimation can be performed, but the amount of addition operations increases and the receiver becomes more complex
Solution Approach 1:
The received signal sequence is divided into multiple blocks, each containing a predetermined number of samples. The correlation computation is performed separately for each block, allowing the use of simplified computation methods for each segment rather than processing the entire long sequence at once, thereby reducing the complexity of the receiver while maintaining synchronization performance.
Solution Approach 2:
The patent changes the computation parameter from full linear or circular correlation to a simplified block-based correlation method. By processing smaller blocks with predetermined sample sizes, the number of addition operations is significantly reduced while still achieving the required synchronization and channel estimation functions.
2Measurement precision
If the input sequence stored in memory is accessed continuously for correlation computation, then correlation between input sequence and PN sequence can be computed, but the operational speed is lowered and operational efficiency is reduced
Solution Approach 1:
The input sequence is segmented into multiple blocks for independent processing. Each block is processed separately through the correlation computation pipeline, allowing parallel processing and reducing the continuous memory access requirement. This segmentation enables the system to maintain computation accuracy while significantly improving operational speed by avoiding sequential access to the entire input sequence.
Solution Approach 2:
The received signal is pre-processed and stored in block form before correlation computation. By organizing the data into predetermined blocks in advance, the system eliminates the need for continuous memory access during correlation computation, as each block can be independently fetched and processed, thereby improving operational efficiency without compromising correlation accuracy.
Data Source
AI summary
The present invention relates to a method for computing correlation of a PN sequence and a circuit thereof. A plurality of input values of an input sequence is summed up to give a first sum. A PN sequence comprising a plurality of first values and a plurality of second values, which correspond to the plurality of input values, are received. Summing up the plurality of input values corresponding to the plurality of first input values in the PN sequence gives a second sum. According to the first sum and the second sum, a correlation value is given. The present invention uses a simple method for computing correlation of a PN sequence. Hence, the operation efficiency is enhanced and the time to give the correlation of the PN sequence is shortened.