SCMA Codebook Phase Rotation Between Layers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication technologies face challenges in efficiently encoding and decoding information over shared network resources, particularly with non-orthogonal encoding techniques that can lead to increased complexity and errors in signal decoding.
Innovation Solution
A codebook design that incorporates phase rotation between layers, optimizing modulation and bit mapping based on symbol decoding error statistics, and using sparse code multiple access (SCMA) techniques to enhance spectral efficiency and error reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If non-orthogonal encoding techniques are used to send more information over a given resource, then spectral efficiency is improved, but decoding accuracy deteriorates
Solution Approach 1:
The patent applies phase rotation transformations to codebook layers, changing the parameter of signal phase to improve orthogonality. By rotating layers in the complex plane using phase factors e^(jθ), the system maintains non-orthogonal encoding for high spectral efficiency while improving decoding accuracy through enhanced signal separation
Solution Approach 2:
The patent introduces phase rotation as an additional dimension of signal processing in the complex plane. By operating in the complex domain with multiple layers that can be rotated independently, the system increases the dimensional separation between signals, allowing more information to be transmitted while maintaining decodability
2Productivity
If non-orthogonal encoding techniques are used to increase information capacity, then data throughput is improved, but decoding complexity increases
Solution Approach 1:
The patent applies phase rotation to codebook layers in advance, before the actual encoding and transmission process. This preliminary transformation pre-conditiones the signals to be more easily separable at the receiver, reducing the complexity of decoding operations required to recover the transmitted data
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Various aspects of the disclosure relate to a codebook design that defines phase rotation on one or more layers of a codebook. This codebook may be used, for example, for sparse code multiple access (SCMA) encoding. One feature pertains to a method of communication that includes receiving at least one input signal, and mapping each of the at least one input signal to a corresponding layer of a codebook, where the codebook defines phase rotation between the layers. The method may further include generating a coded signal for each of the at least one input signal on each corresponding layer based on the codebook, and generating an output signal based on each generated coded signal.