Orthogonal Code Chip Permutation for Power Amplifier Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In wireless communication systems, the existing code-division multiplexing techniques face challenges in evenly distributing peak and zero values of demodulation reference signals, leading to power fluctuations that affect the efficiency of power amplifiers in base stations, especially when the number of layers exceeds four.
Innovation Solution
The proposed method involves using different orthogonal matrices for different layers of demodulation reference signals, with specific chip order changes and cyclic shifts to achieve even power distribution across time and frequency domains, maintaining compatibility with existing standards like LTE-Advanced Release-9.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional orthogonal codes based CDM technique is used, then demodulation reference signals can be multiplexed, but power fluctuations occur and power amplifier efficiency deteriorates
Solution Approach 1:
The patent applies local quality by modifying the chip order specifically in the time-domain orthogonal codes while keeping the frequency-domain structure intact. This localized modification to the code structure (changing chip permutation in specific positions) achieves even power distribution without affecting the overall CDM multiplexing functionality, thereby resolving the power fluctuation issue while maintaining reference signal multiplexing capability.
Solution Approach 2:
The patent changes the parameter of chip order in the orthogonal codes. By permuting the chip sequence in the time-domain orthogonal codes (e.g., changing from standard Walsh code sequence to a reordered sequence), the patent transforms the power distribution characteristics of the multiplexed signals, achieving more uniform power levels across different layers and reducing power amplifier efficiency loss.
2Productivity
If conventional orthogonal codes are used, then signal multiplexing is achieved, but peak and zero values are not evenly distributed
Solution Approach 1:
The patent applies local quality by modifying the chip order specifically in the time-domain orthogonal codes while keeping the frequency-domain structure intact. This localized modification to the code structure (changing chip permutation in specific positions) achieves even power distribution without affecting the overall CDM multiplexing functionality, thereby resolving the power fluctuation issue while maintaining reference signal multiplexing capability.
Solution Approach 2:
The patent changes the parameter of chip order in the orthogonal codes. By permuting the chip sequence in the time-domain orthogonal codes (e.g., changing from standard Walsh code sequence to a reordered sequence), the patent transforms the power distribution characteristics of the multiplexed signals, achieving more uniform power levels across different layers and reducing power amplifier efficiency loss.
3Quantity of substance
If more than four layers are multiplexed, then capacity increases, but power fluctuation problem worsens
Solution Approach 1:
The patent applies local quality by modifying the chip order specifically in the time-domain orthogonal codes while keeping the frequency-domain structure intact. This localized modification to the code structure (changing chip permutation in specific positions) achieves even power distribution without affecting the overall CDM multiplexing functionality, thereby resolving the power fluctuation issue while maintaining reference signal multiplexing capability.
Solution Approach 2:
The patent changes the parameter of chip order in the orthogonal codes. By permuting the chip sequence in the time-domain orthogonal codes (e.g., changing from standard Walsh code sequence to a reordered sequence), the patent transforms the power distribution characteristics of the multiplexed signals, achieving more uniform power levels across different layers and reducing power amplifier efficiency loss.
Data Source
Figure 1(A)~1(D)
Figure 2~3
Figure 4~5
AI summary
The present disclosure provideds an orthogonal codes based code division multiplexing method of performing the code division multiplexing of demodulation reference signals in multiple layers of resource blocks by using orthogonal matrices, the method comprising: changing the order of chips in particular rows of a first orthogonal matrix to obtain a second orthogonal matrix with the changed order of chips; and multiplying the chips in respective rows of the second orthogonal matrix by the demodulation reference signals in corresponding layers of resource blocks correspondingly in the time direction to obtain code division multiplexing signals. The technical scheme of the present disclosure can improve the power jitter situation of downlink signals on the time, thereby the usage efficiency of the power amplifier at the base station side can be improved, meanwhile the dual-orthogonality on the time domain and the frequency domain is obtained, and the performance of the demodulation reference signals on selective channels on the time domain or the frequency domain is improved.