汽車(chē)的無(wú)線趨勢(shì)

　　多年來(lái)，它都是關(guān)于GPS和藍(lán)牙的。今天，無(wú)線汽車(chē)技術(shù)中心對(duì)移動(dòng)電話集成（手機(jī)是唯一的無(wú)線板裝置由汽車(chē)制造商接受）以及開(kāi)發(fā)智能，主動(dòng)安全系統(tǒng)結(jié)合了輸入GPS、雷達(dá)傳感器，激光雷達(dá)（光探測(cè)和測(cè)距）的光學(xué)傳感器和攝像機(jī)來(lái)確定相對(duì)于其他車(chē)輛馬路然后警告潛在的危害汽車(chē)的位置。不久，在車(chē)上的無(wú)線應(yīng)用程序可能包括V2V（車(chē)）通信允許汽車(chē)無(wú)線“談話”，彼此。

　　本文將在汽車(chē)無(wú)線系統(tǒng)的現(xiàn)狀和發(fā)展趨勢(shì)入手，識(shí)別，理解的應(yīng)用如輪胎壓力監(jiān)測(cè)系統(tǒng)（TPMS）、遙控鑰匙（RKE）和訪問(wèn)移動(dòng)到新生的車(chē)載技術(shù)如近場(chǎng)通信（NFC），在車(chē)內(nèi)連接和不太遠(yuǎn)的潛力車(chē)輛駕駛自己的夢(mèng)想。我們還將對(duì)最近在2013屆國(guó)際消費(fèi)電子展上展示的“智能汽車(chē)”演示進(jìn)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）.