Based IEEE802.15.4/ZigBee Voice Communication Technology Research And Implementation

ZigBee technology is a short-range, low-complexity, low-power, low-speed, low-cost wireless networking technology. Its main features include:multi-hop transmission (multi-hop relay)mechanism for the expansion of network performance easily deploye, as well as self-organizing and self-healing ability. ZigBee traditionally mainly used in home automation, industrial automation, inventory management, product quality control, wireless sensor monitoring, and positioning in such areas as fire safety, and its non-real-time data transmission of data. Wireless voice communication is a real-time data transmission,while the realization of wireless voice communication ZigBee standard is not the first goal, but in many areas in the absence of voice communication, so that it will be very much constrained applications; On the other hand, there is an urgent need Layout and difficult conditions (such as underground mine rescue, fire rescue ) ,ZigBee communication technology with other irreplaceable advantages, such as the use of ZigBee network to a two-way voice transmission is a very great practical value; At the same time, wireless sensor networks Applications, is also a sound sensor, transmission of voice sampling data is sound sensing application of the basic requirements, so this IEEE802.15.4/ZigBee papers for the application of environment, to realize voice communication study.Based on the design of this issue CC2430 chip Zigbee hardware modules tested in the open environment of the line-of-sight transmission distance of 30 meters; On this basis, the design based on the IEEE802.15.4 voice communication system program, developed hardware test platform, Research for the short-range wireless voice communications technology. Voice communication programs to make full use of the performance characteristics of the CC2430 SoC, the use of the chip's internal ADC and PWM completion of the sampling and playback voice, not the use of external voice codec devices and the use of the very few external devices. In order to meet the 250Kb/s wireless transfer rate at the same time to ensure voice quality, the use of on-chip CC2430 of 8051 to achieve a single-chip core ADPCM compression algorithm, Optimized ADPCM algorithm, Encoding and decoding times for 20us and 18us, voice To reduce the rate of 32Kb / s. Reduce the bandwidth occupied, and improve the anti-jamming capability. After validation testing, the room is not in the shelter conditions, the system is well positioned to achieve real-time wireless transmission of voice, transmitting power is less than 0 dBm, voice delay is less than 25ms, transmission distance of 15 meters, MOS voice quality test scores of 3 or more. The program hardware simple, low-cost and low power consumption, can be applied to underground mine production, wireless sensor networks, fire, security monitoring in the area and expand the scope of application of IEEE802.15.4 .