Hybrid NOMA Scheme Based on Subcarrier Index Modulation in Backscatter
The uplink of an environmental backscattering communication system based on NOMA in the power domain often completes user pairing through distance.The dual channel fading of the passive backscattering system makes the remote edge devices unable to meet the communication power demands or the minimum Signal-to-Interference-Noise Ratio(SINR)constraint for decoding.In order to solve the above problems,a hybrid uplink NOMA scheme of OFDM and OFDM with Index Modulation(IM)is proposed,which is composed of a tag modulation scheme and a reflection coefficient adjustment scheme.OFDM-IM provides better energy efficiency and enables devices with low power level to meet communication conditions.The Backscatter Devices(BD)flexibly selects OFDM or OFDM-IM according to the received power level,and superimposes them in the power domain.By adjusting the reflection coefficient to ensure the power difference of superimposed signals,the receiver uses the power level to perform multi-user detection.The experimental results show that the scheme can effectively improve the success rate of remote user decoding,and the increase in the number of decoding users improves the system capacity.
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维普
