As a unique multiple access system based on the mcm technology , the orthogonal frequency division multiple access ( ofdma ) is a promising technology for bws 作為一種基于mcm的特殊多址接入技術(shù),在寬帶無線城域網(wǎng)建設(shè)中, ofdma接入技術(shù)有著其特有的優(yōu)點(diǎn)及廣泛的發(fā)展前景。
Due to the data transmission characteristics between tags and reader , space division multiple access ( sdma ) , frequency division multiple access ( fdma ) and code division multiple access ( cdma ) are applied in a limited way in rfid system . therefore , time division multiple ( tdma ) has been generally accepted . according to tdma , there are aloha protocol , s - aloha , binary - tree protocol , clipped binary - tree protocol and others 解決這個問題必須要用到多路存取法,針對射頻識別系統(tǒng)中閱讀器與應(yīng)答器之間的通信特點(diǎn),空分多路法、頻分多路法、碼分多路法在rfid系統(tǒng)中應(yīng)用都受到一定的限制,只能應(yīng)用到一些特定的場合,一般采用時分多路法,按照時分多路法的算法有aloha算法、時隙aloha算法、二進(jìn)制樹型搜索算法、修剪枝的二進(jìn)制樹型搜索算法等防碰撞算法協(xié)議,分析了各自特點(diǎn)以及存在的缺點(diǎn)。