汽车的无线趋势

　　汽车的无线趋势

　　多年来，它都是关于GPS和蓝牙的。今天，无线汽车技术中心对移动电话集成（手机是唯一的无线板装置由汽车制造商接受）以及开发智能，主动安全系统结合了输入GPS、雷达传感器，激光雷达（光探测和测距）的光学传感器和摄像机来确定相对于其他车辆马路然后警告潜在的危害汽车的位置。不久，在车上的无线应用程序可能包括V2V（车）通信允许汽车无线“谈话”，彼此。

　　本文将在汽车无线系统的现状和发展趋势入手，识别，理解的应用如轮胎压力监测系统（TPMS）、遥控钥匙（RKE）和访问移动到新生的车载技术如近场通信（NFC），在车内连接和不太远的潜力车辆驾驶自己的梦想。我们还将对最近在2013届国际消费电子展上展示的“智能汽车”演示进行回顾。

　　Tire-pressure-monitoring systems （TPMS）

　　A tire-pressure-monitoring system， as the name suggests， lets the driver know if there is a problem with tire pressure. Analysts at TechNavio （the syndicated research wing of Infiniti Research） predict the global market for tire pressure monitoring systems to grow at a CAGR of 6.9 percent between 2011 and 2015. According to the analysts this growth is basically due to passenger safety initiatives governments have put in effect.

　　The core technology behind direct measurement TPMS is the RFIC. Typical TPMS systems monitor tire pressure indirectly by using the vehicle‘s anti-lock system to detect changes in rotational speed associated with the decreased radius of a deflated tire. Direct measurement methods， however， must employ low-frequency RF devices to transmit tire pressure measurements to vehicle safety management systems. （See the TechZone article “Low-Frequency RFIC Solutions for Tire-Pressure-Monitoring Systems” for more details）。

　　As an example of a typical TPMS， consider Melexis Technologies’ approach （Figure 1）， which includes the MLX71122 receiver （27 to 930-MHz FSK/FM/ASK， multichannel programmable）， the MLX72013 transmitter （433-MHz ASK/FSK） and the MLX91801 TPMS sensor （Figure 1）.