Based On The Low Intercept Of The Two-dimensional Spread Spectrum Wireless Communication Equipment Design And Realization

Nowadays, wireless tapping devices have become widely used in espionage activities in various countries. The transmission power is generally between 0dBm and 10dBm. If the transmission power is greater than 10dBm, it is easily intercepted by anti-eavesdropping equipment. Reducing the transmission power is to prevent the signal being intercepted an effective way.Two-dimensional spread spectrum technology can not only reduce the signal power spectral density, but also has anti-jamming, anti-fading and anti-interception characteristics. Therefore, the paper gives the program that uses two-dimensional spread spectrum technology, designs and implementations a low interception wireless communication devices.First, it summarizes the technology status of two-dimensional spread spectrum and digital intermediate frequency, and introduces the generalized two -dimensional spread spectrum technology that combines direct sequence spread spectrum with multi-carrier code division multiple access technology. It is the promotion of the traditional one-dimensional spread spectrum technology. Signal spectrum extends in the time domain and frequency domain.at the same time. In addition, it describes the digital intermediate frequency technology from the sampling theorem, rate transforming and digital filtering.Second, it designs and implements the hardware platform of the wireless communication devices from requirement analysis. It briefly describes the structure of the common transceiver and their advantages, and their disadvantages. Next, it introduces the transceiver framework, and selects the core devices, and gives the overall structure of transceiver hardware platform. Then, it designs the function modules of the circuit, and draws a diagram of the chip on the Altium Designer software platform. Last, on the Candence Allegro software platform designs the transceiver printed circuit board from the layout, stack and route.Finally, it debugs and tests hardware platform of the transmitter and receiver, and analyzes the test results. Debugging the power of the hardware platform, programmable devices and other functional modules is order to ensure that the chip can word properly. Then, it builds the test platform, and tests sensitivity, transmitting power, communi- cation distance and other parameters indicators, and analyzes the measured results too. The results show that the minimum transmission power of the device is ?38.34dBm, and the receiver sensitivity is about ?114dBm under the condition of the spreading gain in 36dB.This paper designs a low interception wireless communication devices that have successfully accomplished acceptance. It is verified that two-dimensional spread spectrum technology is feasible in the engineering, and has important practical value and engineering significance.