Hybrid Spatial Phase Modulation for RIS Efficiency
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Solution Overview
Problem
Conventional spatial modulation methods using reconfigurable intelligent surfaces (RIS) that maximize the power of a single receive antenna by adjusting the forwarding phase result in low modulation efficiency.
Innovation Solution
A modulation method that determines a forwarding pattern and phase modulation manner based on a bitstream and a mapping relationship, incorporating indices of both transmit and receive antennas, as well as assistance node areas, to perform higher-order spatial modulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If spatial modulation is performed by maximizing power of one receive antenna by adjusting RIS forwarding phase, then the system can be implemented with simple phase adjustment, but the modulation efficiency is low
Solution Approach 1:
The patent combines spatial modulation and phase modulation into a unified hybrid modulation scheme. The RIS forwarding phase is used to maximize receive antenna power (spatial modulation), while additional phase shifts are applied to convey extra information (phase modulation). This merging of two modulation techniques resolves the contradiction by maintaining implementation simplicity through RIS phase adjustment while significantly improving modulation efficiency through the added phase dimension.
Solution Approach 2:
The patent introduces an additional modulation dimension by applying phase modulation on top of spatial modulation. Instead of solely relying on the spatial dimension (which antenna receives the signal), the system also utilizes the phase dimension to encode additional information. This dimensional expansion resolves the contradiction by keeping the spatial modulation mechanism simple while adding efficiency through the phase dimension.
2Device complexity
If conventional spatial modulation uses only receive antenna index, then the modulation scheme is simple, but the information transmission capacity is limited
Solution Approach 1:
The patent merges spatial modulation (using receive antenna index) with phase modulation (using forwarding phase) to create a hybrid scheme that transmits more information per symbol. The receive antenna index conveys one part of the information while the phase modulation conveys additional bits, thereby increasing information transmission capacity without significantly increasing system complexity.
Solution Approach 2:
The patent transitions from one-dimensional spatial modulation (antenna index only) to a two-dimensional modulation scheme by adding phase as a second dimension. This allows the system to encode more information by utilizing both the spatial dimension (which antenna) and the phase dimension (phase shift amount), effectively increasing information transmission capacity while maintaining reasonable complexity.
Data Source
AI summary
This application relates to the field of communications technologies, and discloses a modulation method and apparatus, a communications device, and a readable storage medium. The method includes: obtaining a bitstream to be transmitted; and determining, based on a bit in the bitstream and a mapping relationship, a forwarding pattern and a manner of modulating a forwarding phase in the forwarding pattern, where the mapping relationship is used to indicate a mapping relationship between the bit, the forwarding pattern, and a target index, and is used to indicate a mapping relationship between the bit and the phase modulation manner; and the target index includes at least one of the following: an index of a transmit antenna, an index of a receive antenna, and an index of an area after division of an array of assistance nodes.