

摘 要: 隨著無線通信技術(shù)在實(shí)際生活中的普及,同處于2.4 GHz ISM開放頻段上的不同種無線傳輸技術(shù)間的相互干擾問題變得日益突出。在此對(duì)多模異構(gòu)系統(tǒng)中藍(lán)牙信號(hào)與ZigBee信號(hào)間的干擾現(xiàn)象進(jìn)行分析,并設(shè)計(jì)出基于馬爾科夫鏈概念(Markov chain concept)的ZigBee傳輸網(wǎng)絡(luò)的簡(jiǎn)易數(shù)學(xué)模型。通過數(shù)學(xué)模型來分析ZigBee設(shè)備受藍(lán)牙同頻異種信號(hào)干擾而導(dǎo)致的數(shù)據(jù)吞吐量和空閑信道評(píng)估(CCA)異常的情況。
關(guān)鍵詞: 馬爾科夫鏈; ZigBee; 藍(lán)牙; 互擾
中圖分類號(hào): TN926?34 文獻(xiàn)標(biāo)識(shí)碼: A 文章編號(hào): 1004?373X(2015)24?0104?03
Research on mutual Interference characteristics ofZigBee and
Bluetooth heterogeneous network
ZHOU Chen, FAN Yuqi, ZHANG Jinlong
(Nanjing Normal University, Nanjing 210000, China)
Abstract: With the popularity of wireless communications technology in actual life, the mutual interference among different kinds of wireless transmission technologies used in the same frequency band of 2.4 GHz is becoming more and more prominent. The interference between Bluetooth signal and ZigBee signal in multimode heterogeneous system is analyzed in this paper. A simple mathematical model of ZigBee transmission network based on Markov chain concept is designed. The ZigBee device’s abnormal conditions in the data throughout and CCA (clear channel assessment) caused by the interference of Bluetooth heterogeneous signals with same frequency are analyzed by means of the mathematical model.
Keywords: Markov chain; ZigBee; Bluetooth; mutual interference
0 引 言
近年來用戶對(duì)于更便捷的使用公用頻段的呼聲尤其高漲,應(yīng)聲而來的是各種處于公用頻段上的無線傳輸技術(shù)在現(xiàn)實(shí)應(yīng)用中得到了極大的普及,如無線局域網(wǎng)(WiFi)、藍(lán)牙(Bluetooth)、ZigBee[1]、無線USB(Wireless USB)等技術(shù)手段應(yīng)用到了生活中的各行各業(yè)。在所有的這些WPAN技術(shù)中,企業(yè)和個(gè)人用戶對(duì)于ZigBee[2]和藍(lán)牙技術(shù)尤其青睞,這得益于它們的低成本和低能耗這兩個(gè)特性。但是鑒于它們都是工作于2.4 GHz頻段上的無線傳輸協(xié)議,因此它們之間存在互相干擾的問題。
麻省理工學(xué)院(MIT)的豪伊特(Dr.Howitt)和古鐵雷斯博士(Dr.Gutierrez)曾通過實(shí)驗(yàn)分析了ZigBee和WLAN網(wǎng)絡(luò)相互間干擾的特性,并定性的給出了其干擾區(qū)域。西科拉(Dr.Sikora)和格羅扎博士(Dr.Groza)也曾通過實(shí)驗(yàn)指出處于異構(gòu)網(wǎng)絡(luò)中的WLAN和藍(lán)牙在傳輸數(shù)據(jù)時(shí)存在丟幀現(xiàn)象。因此本文對(duì)于處在同一網(wǎng)絡(luò)中的ZigBee/藍(lán)牙信號(hào)的忽擾現(xiàn)象的研究十分有必要。
1 ZigBee/藍(lán)牙異構(gòu)網(wǎng)絡(luò)構(gòu)成
多模異構(gòu)無線數(shù)據(jù)傳輸系統(tǒng)在生活中的應(yīng)用十分廣泛,涉及醫(yī)療、強(qiáng)電、工業(yè)控制、安防等方方面面。……