對儀器設施在藍牙頻率測定中的效用
1藍牙跳頻選擇內核的結構
根據不同狀態,使用不同設備的藍牙地址。選擇內核輸出構成偽隨機序列,根據不同係統覆蓋79跳頻點或者23跳頻點。以79跳係統為例,選頻機製選擇一個頻點段,該段由覆蓋64M Hz的32個跳頻點組成,並以隨機順序每次訪問其中一個頻點。然後,再選擇下一個不同32頻點段。輸入信號X為32頻點段相位控製信號, Y1、Y2分別表示主從傳輸與從主傳輸,信號A D決定段內頻點,信號E F映射頻率值。內核中第二次相加輸出信號尋址跳頻頻率寄存器,寄存器中頻點排列方式如下:首先順序排列偶數頻點,然後排列奇數頻點,這樣, 32頻點段占用頻率範圍為64M Hz.
2虛擬儀器技術的應用
跳tiao頻pin作zuo為wei藍lan牙ya基ji帶dai係xi統tong的de關guan鍵jian技ji術shu,其qi理li論lun性xing較jiao強qiang,學xue生sheng難nan以yi形xing成cheng感gan性xing認ren識shi。此ci外wai,由you於yu藍lan牙ya采cai用yong很hen高gao的de跳tiao頻pin速su率lv,一yi般ban設she備bei無wu法fa觀guan察cha藍lan牙ya係xi統tong實shi際ji產chan生sheng的de跳tiao頻pin圖tu案an。針zhen對dui這zhe種zhong情qing況kuang,本ben實shi驗yan采cai用yong虛xu擬ni儀yi器qi技ji術shu對dui實shi際ji係xi統tong進jin行xing仿fang真zhen。通tong過guo編bian程cheng實shi現xian跳tiao頻pin選xuan擇ze內nei核he算suan法fa,搭da建jian實shi驗yan界jie麵mian,顯xian示shi跳tiao頻pin圖tu案an,實shi現xian藍lan牙ya高gao速su跳tiao頻pin方fang案an的de可ke視shi化hua。係xi統tong在zaiWindows 2000下使用VC+ + 6 0作為應用程序開發工具。
設計本實驗時,本著由淺入深,從感性認識到理性認識的原則,分為4個部分:區分跳頻與非跳頻係統:設定虛擬儀器的跳頻速率、載頻、信(xin)息(xi)碼(ma)等(deng)參(can)數(shu),同(tong)時(shi)觀(guan)察(cha)跳(tiao)頻(pin)與(yu)非(fei)跳(tiao)頻(pin)兩(liang)路(lu)動(dong)態(tai)演(yan)示(shi),進(jin)而(er)了(le)解(jie)兩(liang)種(zhong)係(xi)統(tong)的(de)區(qu)別(bie)。考(kao)慮(lv)到(dao)都(dou)是(shi)采(cai)用(yong)頻(pin)率(lv)調(tiao)製(zhi),有(you)著(zhe)一(yi)定(ding)的(de)共(gong)性(xing),本(ben)實(shi)驗(yan)中(zhong)非(fei)跳(tiao)頻(pin)係(xi)統(tong)選(xuan)取(qu)2FSK係統來進行對比;藍牙RF係統模型:設定虛擬儀器的頻偏、信(xin)息(xi)碼(ma)流(liu)等(deng)參(can)數(shu),觀(guan)察(cha)在(zai)單(dan)個(ge)頻(pin)點(dian)的(de)波(bo)形(xing)和(he)跳(tiao)頻(pin)波(bo)形(xing)的(de)動(dong)態(tai)演(yan)示(shi),使(shi)學(xue)生(sheng)從(cong)感(gan)觀(guan)上(shang)理(li)解(jie)藍(lan)牙(ya)基(ji)帶(dai)跳(tiao)頻(pin)傳(chuan)輸(shu)的(de)基(ji)本(ben)原(yuan)理(li),為(wei)進(jin)一(yi)步(bu)深(shen)化(hua)認(ren)識(shi)奠(dian)定(ding)基(ji)礎(chu);藍牙跳頻同步模型:xuniyiqigeichutiaopintongbumoxingkuangtu,shouxianshedingliangshebeicanshuzhi,lanyadizhiheshizhong。zaitongyiyanshikuangnei,guanchalianggeshebeitiaopinxulietiaobiandeguilv。dangshedingcanshuwanquanxiangtongshi,lianggeshebeidepinlvtiaobianguilvwanquanyizhi,jidadaotiaopintongbu。gaibianqizhongyigecanshu,guanchatiaobianguilvfashengdegaibian,lejiebutongcanshuduitiaopinxuliedeyingxiang;跳頻選擇內核:虛擬儀器隨機給出設備參數值。學生根據設備參數,填寫選擇內核框圖的輸入值,並計算輸出值,與虛擬儀器產生的結果進行比較。
下麵以藍牙RF係統模型為例,介紹虛擬儀器技術在教學實驗中的應用。
lanyatiaopinxitongzhong,xinxizaigegepindianshiyikaozaibojiashangyidingdepinpianlaijinxingchuanshude,tongguozhengfuliangzhongpinpianlaiqufenerjinzhimazhi。xuniyiqizhongdaishezhidexitongcanshubaokuochuanmalv、頻偏、載zai波bo頻pin偏pian以yi及ji信xin息xi碼ma值zhi。儀yi器qi根gen據ju學xue生sheng設she定ding的de信xin息xi碼ma值zhi,在zai界jie麵mian右you上shang角jiao的de圖tu框kuang中zhong顯xian示shi單dan個ge頻pin點dian處chu的de信xin息xi碼ma波bo形xing示shi意yi圖tu,縱zong軸zhou代dai表biao頻pin偏pian值zhi,橫heng軸zhou代dai表biao單dan位wei時shi間jian值zhi(通過設定的傳碼率得到)。zaibopinpianquedingzhongxinpinlvdeweizhi,yiqiduixueshengdeshedingzhishouxianjinxingpanduan,ruoshedingzaibopinpianzhiguoda,jiangchuxianbaocuoduihuakuang,tishizhongxinjinxingshezhi。wanchengsuoyoucanshushezhihou,dianxuandongtaiyanshixiang。yiqisuijishengchengyigelanyadizhiheyigebendishizhongzhi,anzhaodingyidetiaopinxuanzeneihesuanfa,chanshengtiaopinxuliebingyingshetiaopinpindianzhi,zaitiaopinyanshikuangzhongjinxingdongtaiyanshi。zaidangepindianshangdepinpiangenjuxueshengshedingdexinximazhidedao。
3結束語
藍(lan)牙(ya)教(jiao)學(xue)實(shi)驗(yan)係(xi)統(tong)使(shi)學(xue)生(sheng)真(zhen)正(zheng)認(ren)識(shi)一(yi)個(ge)完(wan)整(zheng)的(de)無(wu)線(xian)通(tong)信(xin)係(xi)統(tong),而(er)非(fei)停(ting)留(liu)在(zai)原(yuan)理(li)階(jie)段(duan),利(li)用(yong)虛(xu)擬(ni)儀(yi)器(qi)技(ji)術(shu)將(jiang)通(tong)信(xin)原(yuan)理(li)的(de)基(ji)本(ben)知(zhi)識(shi)完(wan)整(zheng)地(di)體(ti)現(xian)在(zai)藍(lan)牙(ya)實(shi)驗(yan)中(zhong),深(shen)入(ru)理(li)解(jie)如(ru)何(he)掌(zhang)握(wo)協(xie)議(yi)、實現協議的方法,從而提高學生對無線通信係統的認識深度,為將來學習和從事其他無線通信係統的研究開發工作奠定基礎。中國糧油儀器網 http://98fo.cn/



