Design Of Demodulator In Low Power, Long Range Wireless Sensor

It is generally believed that, internet of things is the third wave after the computer, the Internet and mobile communication network of information industry. The perception layer of internet of things consists of a large amount of small volume, low cost, wireless communication, sensor, data processing of sensor nodes, the wireless sensor node is the basic unit of perception layer, the stable operation of the node elementarily guarantee the reliability of the network. The most important part of the node is A/D unit and communication unit, usually the two units are integrated into a chip, which we called a wireless sensor chip.FPGA (Field Programmable Gate Array), since it has many good characteristics such as programmable, multiple rewritable, it has been developing rapidly in recent years, and has been widely used in all kinds of electronic design. This paper is based on FPGA technology, try to design a demodulator which is used in wireless sensor chip.This paper realize FSK demodulator design in the way of digital differential detection demodulation, in this paper, the functions of each of module in the system and the realization of form is been discussed, the paper also gives the specific design process, and one module of the system digital low-pass filter design is described in detail. At last, after function simulation of system in software tools, system is download in FPGA development board to run, this is called the board level verification, the system design goal is the successfully realized.This paper designs a modulator which based on the FPGA via a Cyclone II series development board, the development board belongs to the monolithic economy FPGA, has the advantages of low cost. At the same time the system in the design is modular and it can be conveniently transplantated to other FPGA board, which is used in digital communication system, so it improves the applicability of the design.