Ultra-low power consumption OFDMA wireless downlink system and method based on non-linear mixing

Abstract

The invention provides an ultra-low power consumption OFDMA wireless downlink method and system based on non-linear mixing, and the method comprises the steps: S1, loading original bit streams of different users on subcarriers through coding, constellation diagram mapping and interleaving modes, generating OFDM signals, and transmitting the generated OFDM signals to a user terminal through a transmitter; and S2, enabling the user terminal to carry out passive down-conversion on the OFDM signal sent by the transmitter through a nonlinear device, and achieving selective demodulation of subcarriers in the OFDM signal after down-conversion through local frequency shifting. The tag is used as an Internet-of-Things node and has the working characteristic of ultra-low power consumption; and down-conversion is realized by utilizing the nonlinear characteristic of a completely passive diode, selective demodulation of subcarriers is realized through secondary frequency conversion of a radio frequency switch, the power consumption of the down-conversion device mainly comes from the power consumption of secondary frequency mixing of the radio frequency switch and a comparator, and the peak power consumption of the down-conversion device is predicted to be lower than 200 microwatts under the communication bandwidth of 20 MHz.

Description

technical field [0001] The present invention relates to the technical field of low power consumption communication, analog radio frequency circuit and wireless communication, in particular, relates to an ultra-low power consumption OFDMA wireless downlink system and method based on nonlinear frequency mixing. Background technique [0002] The Internet of Things can make our lives smarter and more convenient. However, the core component of the Internet of Things: the mobile terminal is always limited by the power consumption problem and it is difficult to be completely solved. In recent years, in the direction of wireless networks and systems, the research on backscatter has attracted extensive attention. Since there is no need for actively transmitting power devices, devices based on backscattering communication methods can relatively reduce power consumption by hundreds or thousands of times. The latest backscatter technology can also achieve a data return rate of 96Mbps ...

AI Technical Summary

Problems solved by technology

The previous backscattering work continued the low-power design of the last century: using a completely passive diode to passively detect the envelope signal for broadcast communication; however, this method has low efficiency defects, especially in equipment In a large number of dense scenarios, the broadcast downlink constrains the efficiency of the backscatter network and limits its application

OFDMA downlink is currently a multi-user downlink solution widely used in wireless systems such as LTE. However, it is based on the characteristics of down-conversion, amplifier and FFT modules, making it difficult for backscatter tags to support the required power consumption.

However, due to the difficulty of implementing high-Q filters, down-conversion circuits are required, and frequency-domain sampling relies on high-power FFT computing modules, these have become two major factors that make it difficult to achieve low-power OFDMA downlinks.

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