Frequency spectrum dynamic control method and system for OFDMA backscatter network

Abstract

The invention provides a frequency spectrum dynamic control method and system for an OFDMA backscatter network, and the method comprises the steps: 1, enabling a central control node to obtain networkfrequency spectrum occupation information, and reading the number of active nodes in a frequency spectrum and the total number of current sub-channels; 2, enabling the central control node to encodethe total quantity of the sub-channels, and broadcasting the wireless channels after modulation; 3, enabling a backscatter label to decode the broadcasted modulated wireless channel through a demodulation circuit to obtain a new sub-channel total amount, and taking the sub-channel total amount as a parameter to control the symbol rate in the backscatter communication process. According to the invention, the problem of frequency spectrum waste of a large-capacity OFDMA backscattering network under the condition of a small amount of equipment is solved; the method can also be used for adjustingthe data rate of the network, and the communication reliability can be improved by reducing the symbol rate or increasing the symbol length under the condition that the SNR of the network is poor.

Description

technical field [0001] The present invention relates to the field of communication technology, in particular to a spectrum dynamic control method and system of an OFDMA backscattering network. Background technique [0002] Backscatter communication has attracted extensive attention in the field of IoT in recent years. Its main feature is to use external electromagnetic waves to modulate to realize its own communication. Since electromagnetic waves do not need to be actively generated, even if they are generated for Wi-Fi communication, the power consumption is very low, only tens of microwatts (see NSDI paper by Bryce Kellogg et al. in 2016). However, with the expansion of the scale of the Internet of Things, the multi-access technology has gradually changed from time division multiplexing to frequency domain multiplexing. In 2019, Renjie Zhao and others published "OFDMA-Enabled Wi-Fi Backscatter" on MobiCom, using 48 data subcarriers in the 802.11g protocol to allocate 48...

AI Technical Summary

Problems solved by technology

The network can achieve a physical layer throughput of 12Mbps at full load; however, when the network load is low and only a few (less than 3) tags work, the physical layer throughput of the network is less than 1Mbps

In fact, although the entire 20MHz band is occupied in this case, less than 1MHz is actually utilized

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