Superimposed Signal Phase Rotation for IoT Spectral Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current wireless communication technologies for IoT devices face challenges in achieving high spectrum efficiency without burdensome hardware requirements, particularly for low-cost devices with limited resources, as they often require complex modulation schemes, high signal-to-noise ratios, or intensive computation for error correction.
Innovation Solution
The implementation of rotation codes allows two transmitters to share communication slots, enabling the detection of superimposed signals by changing the relative phase between slots, thereby achieving spectral efficiency and coding gain without the need for complex hardware.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If complex modulation schemes are used to improve bandwidth utilization, then spectrum efficiency is improved, but hardware complexity and cost increase
Solution Approach 1:
The patent applies phase rotation to superimposed signals from multiple transmitters, changing the phase parameter to enable signal separation. This allows complex modulation schemes to be implemented without requiring complex hardware for signal separation, as the phase-rotated signals can be distinguished through simple phase comparison at the receiver
Solution Approach 2:
The patent replaces complex hardware-based signal separation mechanisms with a mathematical/phase-based approach. Instead of using complex physical filters or separators, the system uses phase rotation and superposition principles to enable simple receivers to distinguish multiple transmitted signals
2Use of energy by moving object
If sophisticated error correction is used to operate at reduced power levels, then power consumption is reduced, but computation intensity increases
Solution Approach 1:
The patent applies error correction coding in advance to the data before transmission. By pre-encoding the data with error correction codes, the system enables reliable detection of superimposed signals without requiring intensive real-time computation at the receiver, thus reducing both power consumption and computational burden
3Measurement precision
If transmit power control is implemented to discriminate signals with different power levels, then signal discrimination capability is improved, but device complexity increases
Solution Approach 1:
The patent changes the phase parameter of transmitted signals instead of relying on power level differences. By rotating the phase of superimposed signals from different transmitters, the system enables signal discrimination through phase comparison rather than power level measurement, avoiding the need for complex transmit power control mechanisms
4Productivity
If two transmitters share communication slots with superimposed transmissions, then spectral efficiency is improved, but signal detection difficulty increases
Solution Approach 1:
The patent applies phase rotation to the superimposed signals from two transmitters sharing the same communication slot. By rotating the phase of one or both signals, the receiver can distinguish between the two transmitters through phase comparison, enabling detection of both signals simultaneously without increasing detection difficulty
Solution Approach 2:
The patent introduces phase rotation as an intermediary mechanism that facilitates the separation of superimposed signals. The phase rotation acts as a mediator that transforms the indistinguishable superimposed signals into distinguishable phase-rotated versions, enabling simple detection at the receiver
Data Source
AI summary
Methods and systems are disclosed for sharing a communication resource. Two transmitters seek to use the same two communication slots to transmit two symbols each to a receiver. At each transmitter, data rotation provides two orthogonal combinations of two input symbols which are transmitted in the two slots. An additional phase rotation between slots at one of the transmitters provides phase diversity. The receiver receives superimposed signals from the transmitters, each slot providing information of all four symbols. Joint detection over the two slots provides coding gain and reliable recovery of all four symbols in the two communication slots. Performance results are provided. Disclosed techniques are lightweight and suitable for resource-constrained IoT devices.