汽車的無線趨勢

　　多年來，它都是關于GPS和藍牙的。今天，無線汽車技術中心對移動電話集成（手機是唯一的無線板裝置由汽車制造商接受）以及開發智能，主動安全系統結合了輸入GPS、雷達傳感器，激光雷達（光探測和測距）的光學傳感器和攝像機來確定相對于其他車輛馬路然后警告潛在的危害汽車的位置。不久，在車上的無線應用程序可能包括V2V（車）通信允許汽車無線“談話”，彼此。

　　本文將在汽車無線系統的現狀和發展趨勢入手，識別，理解的應用如輪胎壓力監測系統（TPMS）、遙控鑰匙（RKE）和訪問移動到新生的車載技術如近場通信（NFC），在車內連接和不太遠的潛力車輛駕駛自己的夢想。我們還將對最近在2013屆國際消費電子展上展示的“智能汽車”演示進行回顧。

　　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）.