CDMA Encoding Using Perfect Gaussian Integer Sequences
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Solution Overview
Problem
Current CDMA technologies face limitations in constructing perfect Gaussian integer sequences of arbitrary lengths, which restrict the number of encoding channels and signal to noise ratio, and are inadequate in suppressing channel crosstalk.
Innovation Solution
The implementation of perfect Gaussian integer sequences (PGIS) of arbitrary composite lengths using upsampling techniques, allowing for enhanced system performance by increasing the number of encoding channels and signal to noise ratio, and improving channel crosstalk suppression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional CDMA encoding sequences are used, then the system structure is simple, but the number of encoding channels is limited and signal to noise ratio is insufficient
Solution Approach 1:
The patent segments the sequence construction process into two independent parts: a base sequence of length M and an upsampling factor L. This segmentation allows the complex arbitrary-length sequence generation to be divided into manageable components, where the base sequence can be constructed using traditional methods and the final sequence is obtained by systematic upsampling, thereby reducing overall construction complexity while enabling arbitrary length requirements.
Solution Approach 2:
The patent performs preliminary construction of a base sequence with length M that satisfies perfect autocorrelation properties, then uses this pre-constructed base sequence as foundation for generating arbitrary-length sequences through upsampling. This preliminary action eliminates the need to construct entire arbitrary-length sequences from scratch, significantly reducing computational complexity while maintaining the required autocorrelation characteristics.
2Reliability
If sequence length is increased to improve signal to noise ratio, then signal to noise ratio improves, but channel crosstalk suppression becomes inadequate
Solution Approach 1:
The patent changes the key parameter of sequence construction by enforcing perfect autocorrelation properties at each stage of the upsampling process. By maintaining the condition that the autocorrelation function equals zero for all non-zero shifts, the system achieves both high signal to noise ratio (through adequate sequence length) and effective channel crosstalk suppression (through perfect autocorrelation), resolving the contradiction between these two requirements.
3Adaptability or versatility
If arbitrary length sequences are constructed, then system adaptability improves, but construction difficulty increases
Solution Approach 1:
The patent performs preliminary construction of a base sequence with length M that satisfies perfect autocorrelation properties, then uses this pre-constructed base sequence as foundation for generating arbitrary-length sequences through upsampling. This preliminary action eliminates the need to construct entire arbitrary-length sequences from scratch, significantly reducing computational complexity while maintaining the required autocorrelation characteristics.
Solution Approach 2:
The patent achieves arbitrary length adaptability by changing the upsampling factor L while keeping the base sequence construction method unchanged. This parameter change approach allows the system to adapt to different sequence length requirements simply by adjusting L, without fundamentally altering the construction methodology, thereby maintaining ease of manufacture while improving adaptability.
Data Source
AI summary
A communication receiving apparatus, a signal receiving method thereof, and a signal transmitting method based Code Division Multiple Access (CDMA) technology are provided. A communication transmitting apparatus encodes an original data sequence based on a perfect Gaussian integer sequence (PGIS) to generate a spread signal and transmits a radio frequency (RF) signal including the spread signal. An autocorrelation function of the PGIS conforms to an impulse characteristic, and the PGIS has a spectrum with equal magnitude. The communication receiving apparatus obtains the RF signal from the communication transmitting apparatus and transforms the RF signal into a baseband signal. The baseband signal is de-modulated into a data stream by the communication receiving apparatus. The data stream is recovered into at least one data value of the original data sequence based on the PGIS by the communication receiving apparatus.