height=7 src="s06.files/blue-point.gif" width=7> <SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">干擾方式</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">5</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">，依照跳頻圖案的規(guī)律跟蹤施放大功率的干擾。</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"><SPAN 
            style="mso-spacerun: yes">&nbsp; </SPAN><O:P></O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">這些干擾方式和跳頻通信的關(guān)系正像二人對奕時相互“出子”一樣，當(dāng)雙方的“布子”落在時一頻域棋盤內(nèi)的同一小格時，則干擾有效。因此，跟蹤跳頻圖案施放的干擾策略就是最佳的干擾跳頻通信的策略了。</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"><O:P> </O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">圖</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">6</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">－</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">3</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">給出了方式</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">1</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">和方式</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">4</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的干擾策略與跳頻圖案的關(guān)系。</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"><O:P> </O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%" 
            align=center><SPAN lang=EN-US style="FONT-SIZE: 12pt">&nbsp;<IMG 
            height=407 src="s06.files/s6-03.gif" width=450 border=0><O:P> 
            </O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%" 
            align=center><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">圖</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">6</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">－</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">3<O:P> </O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%" 
            align=center><SPAN lang=EN-US 
            style="FONT-SIZE: 12pt"><O:P></O:P></SPAN><SPAN lang=EN-US 
            style="FONT-SIZE: 12pt"><O:P></O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">圖中示出一種跳頻圖案，方式</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">1</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">干擾策略是在時間上連續(xù)的施放一個窄帶干擾，即第</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">l0</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">個頻率段以斜線表示的干擾帶；方式</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">4</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">干擾策略是在第一個時間段用第一個頻率段進(jìn)行干擾，第二個時間段用第二個頻率段進(jìn)行干擾，依次下去，就形成了沿時頻域模盤對角線上的于擾帶。跳頻圖案中受到這兩種干擾時就用全黑色方塊來表示。由圖中可以看出，干擾方式</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">1</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">只干擾了一個跳頻駐留時間的通信，而干擾方式</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">4</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">則干擾了三個跳頻駐留時間的通信。</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"><O:P> </O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">跳頻圖案的不同，其干擾的效果也不盡相同。當(dāng)跳頻圖案的隨機性越大時，跳頻抗干擾的能力就越強；“棋盤”越大時，即頻率和時間的乘積越大時，可容納的隨機圖案也越多，跳頻圖案本身的隨機性也越大，從而抗干擾能力也越強。</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt; mso-spacerun: yes">&nbsp; 
            </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">所謂抗于擾能力強，實際上是指碰到干擾的概率小。</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"><SPAN 
            style="mso-spacerun: yes">&nbsp;&nbsp; </SPAN><O:P></O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">現(xiàn)代電子戰(zhàn)中，通信方采用跳頻技術(shù)來分散干擾的影響，干擾方則想截獲通信方的信號以減少于擾的盲目性，并盡量作到有的放矢，這就是跟蹤式干擾策</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt; mso-spacerun: yes">&nbsp; 
            </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">略。跟蹤式干擾的有效干擾是有條件的，這個條件除功率因素外，還應(yīng)當(dāng)滿足干擾橢圓的要求，如圖</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">6</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">－</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">4</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">所示。</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"><O:P> </O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%" 
            align=center><SPAN lang=EN-US style="FONT-SIZE: 12pt">&nbsp;<IMG 
            height=354 src="s06.files/s6-04.gif" width=450 border=0><O:P> 
            </O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%" 
            align=center><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">圖</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">6</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">－</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">4<O:P> </O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%" 
            align=center><SPAN lang=EN-US 
            style="FONT-SIZE: 12pt"><O:P></O:P></SPAN><SPAN lang=EN-US 
            style="FONT-SIZE: 12pt"><O:P></O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">圖中的通信方為收、發(fā)信機，干擾機用來對通信的信號進(jìn)行偵聽、處理，然后以同樣的載波頻率施放干擾。為了有效地干擾跳頻系統(tǒng)，在通信頻率跳到新的頻率之前，干擾機必須完成從偵聽到施放干擾的全過程。</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"><O:P> </O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">跳頻系統(tǒng)更換載頻的跳頻間隔時間，就是跳頻信號在空間駐留的時間。根據(jù)收、發(fā)信機的距離</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">d1</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">，干擾機與發(fā)、收信機的距離</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">d2</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">和</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">d3</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">，以及跳頻駐留時間和干擾機施放干擾的處理時間，可以得到以發(fā)射機和接收機為兩個焦點的橢圓。只有當(dāng)干擾機設(shè)置在這個橢圓內(nèi)時，才能使干擾有效，如果干擾機設(shè)置在橢圓之外時，則此跟蹤式干擾策略無效。</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"><O:P> </O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 150%"><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 12pt; mso-spacerun: yes">&nbsp;&nbsp;&nbsp; 
            </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">顯然，為了對付跟蹤式干擾，希望跳頻信號的駐留時間越短越好，讓干擾機來不及施放干擾。因此，希望跳頻通信的跳速應(yīng)當(dāng)盡可能的快才好。這就是目前各國爭先研究快速跳頻通信裝備的原因之一。</SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 150%">　</P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 150%"><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"><O:P></O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; LINE-HEIGHT: 150%"><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt; COLOR: #333399">6.1.4 
            </SPAN><SPAN 
            style="FONT-SIZE: 12pt; COLOR: #333399; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">跳頻技術(shù)指標(biāo)與抗干擾的關(guān)系</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt; COLOR: #333399"><O:P> 
            </O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">考察一個系統(tǒng)的跳頻技術(shù)性能，應(yīng)注意下列各項指標(biāo)：</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"><O:P> </O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 24pt; LINE-HEIGHT: 150%"><IMG 
            height=7 src="s06.files/blue-point.gif" width=7> <SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋體; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">跳頻帶寬</SPAN></P>