Orthogonal Code Matrix for Flexible Low-PAPR Wireless Signals
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Solution Overview
Problem
Existing signal design approaches, such as DFT-s-OFDM, are not flexible enough and have high Peak to Average Power Ratio (PAPR) in wireless communication systems like NR and VLC, limiting their applicability and efficiency.
Innovation Solution
A method using an orthogonal code defined by an encoding matrix C_K with specific properties, allowing for the generation of signals with low PAPR/CM and suitable for high data rate systems, involving partitioning transmission resources into blocks and sub-blocks, and associating each with orthogonal code subspaces for signal transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If DFT-s-OFDM is used to generate signals, then the Peak to Average Power Ratio (PAPR) is reduced, but the system lacks flexibility and has limited applicability to NR and VLC
Solution Approach 1:
The transmission resources are partitioned into blocks, and each block is further partitioned into sub-blocks. Each sub-block is associated with a corresponding code subspace of the orthogonal code, allowing independent processing and mapping of different signal portions to different subspaces, thereby achieving both low PAPR and system flexibility
Solution Approach 2:
The patent employs an orthogonal code with dynamically adjustable parameters including block size B, number of sub-blocks k, and subspace dimensions. The encoding matrix C_K allows flexible configuration of code subspaces S_m to adapt to different transmission requirements, making the system versatile for various applications including NR and VLC
2Productivity
If conventional signal design approaches are used, then implementation is simpler, but data rate and multi-user multiplexing performance are limited
Solution Approach 1:
The patent introduces code domain multiplexing by mapping different sub-blocks to orthogonal code subspaces S_m. This adds a new dimension for signal separation and multiplexing beyond traditional time and frequency domains, enabling high data rates through parallel transmission of multiple users and data streams while maintaining manageable complexity through structured orthogonal codes
3Object-affected harmful factors
If DFT-s-OFDM is applied in VLC, then signal generation is possible, but the PAPR is not as low as in RF communications due to real-valued waveform restriction
Solution Approach 1:
The patent applies different processing and mapping strategies to different sub-blocks within each block. Each sub-block can be independently mapped to specific code subspaces with tailored properties, allowing optimization for local requirements such as real-valued constraints in VLC while maintaining overall system performance and low PAPR
Data Source
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AI summary
An orthogonal code is disclosed, defined by an encoding matrix CK having N rows and N — P + 1 columns, wherein N = P. 2K, K is a positive integer and P is an odd positive integer. In the encoding matrix, no column is equal to another column, and exactly one of the columns of the encoding matrix comprises N elements having the same real non-zero value. Each of the other columns of the encoding matrix comprises exactly (N— L) elements having zero value and exactly L elements having real, non-zero, alternating positive and negative values of the same magnitude, wherein L ∈ {2 K , 2 K -1, 22, 21 }. For each of these columns, the elements of each adjacent pair of the L elements are separated by (N— L)/L elements having zero value. A method of constructing an orthogonal code is also disclosed, together with a method for generation of a signal to be transmitted using the orthogonal code, a corresponding arrangement, a corresponding wireless communication transmitter, and a computer program product.