s02.htm

关于扩频的一些好资料

            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 21.75pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">它定义为频谱扩展前的信息带宽</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 12pt; FONT-FAMILY: Symbol; mso-ascii-font-family: Times New Roman; mso-hansi-font-family: Times New Roman; mso-char-type: symbol; mso-symbol-font-family: Symbol">D</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">F</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">与频带扩展后的信号带宽</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">W</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">之比：</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: 21.75pt; LINE-HEIGHT: 150%" 
            align=center><SPAN lang=EN-US style="FONT-SIZE: 12pt"><SPAN 
            style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp;<B> 
            </B></SPAN><B>G</B></SPAN><B><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＝</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">W</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">／</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 12pt; FONT-FAMILY: Symbol; mso-ascii-font-family: Times New Roman; mso-hansi-font-family: Times New Roman; mso-char-type: symbol; mso-symbol-font-family: Symbol">D</SPAN></B><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"><B>F<SPAN 
            style="mso-spacerun: yes">&nbsp;&nbsp;&nbsp; 
            </SPAN></B><O:P></O:P></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 21.75pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">在扩频通信系统中．接收机作扩频解调后，只提取伪随机编码相关处理后的带宽为</SPAN><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 12pt; FONT-FAMILY: Symbol; mso-ascii-font-family: Times New Roman; mso-hansi-font-family: Times New Roman; mso-char-type: symbol; mso-symbol-font-family: Symbol">D</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">F </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的信息，而排除掉宽频带</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">W</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">中的外部干扰、噪音和其地用户的通信影响。因此，处理增益</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">G</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">反映了扩频通信系统信噪比改善的程度。</SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 21.75pt; 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; TEXT-INDENT: 21.75pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><IMG 
            height=11 src="s02.files/sliver-cirm.gif" width=11> <B><FONT 
            color=#ff6633 size=2>抗干扰容限</FONT></B></SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 21.75pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">是指扩频通信系统能在多大干扰环境下正常工作的能力，定义为：</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: 21.75pt; LINE-HEIGHT: 150%" 
            align=center><B><SPAN lang=EN-US style="FONT-SIZE: 12pt">Mj = G 
            </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">－</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"> [(S/N)out + Ls]<O:P> 
            </O:P></SPAN></B></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 21.75pt; LINE-HEIGHT: 150%" 
            align=center><B><SPAN lang=EN-US 
            style="FONT-SIZE: 12pt"><O:P></O:P></SPAN></B></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 21.75pt; LINE-HEIGHT: 150%"><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">其中：</SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 21.75pt; LINE-HEIGHT: 150%"><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">Mj --- </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">抗干扰容</SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 21.75pt; LINE-HEIGHT: 150%"><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">G --- </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">处理增益</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: 21.75pt; LINE-HEIGHT: 150%"><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">(S</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">／</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">N)out --- </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">信息数据被正确解调而要求的最小输出信噪比</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: 21.75pt; LINE-HEIGHT: 150%"><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">Ls --- </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">接收系统的工作损耗</SPAN></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 21.75pt; LINE-HEIGHT: 150%">　</P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 21.75pt; 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; TEXT-INDENT: 21.75pt; LINE-HEIGHT: 150%"><SPAN 
            lang=EN-US 
            style="FONT-SIZE: 12pt; mso-spacerun: yes">&nbsp;</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'"><FONT 
            face=宋体 color=#008080>例如</FONT></SPAN><FONT face=宋体 
            color=#008080><SPAN lang=EN-US style="FONT-SIZE: 12pt">, 
            </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">一个扩频系统的处理增益为</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">35dB</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">．要求误码率小于</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">l0</SPAN><SUP><SPAN 
            class=unnamed4 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">－</SPAN><SPAN 
            class=unnamed4 lang=EN-US 
            style="FONT-SIZE: 12pt">5</SPAN></SUP><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的信息数据解调的最小的输出信噪比</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">(S/N)out </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＜</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">10 dB</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">，系统损耗</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">Ls</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＝</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">3dB</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">，则干扰容限</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">Mj </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＝</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">35 </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">－</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"> (10 +3) </SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">＝</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"> 22dB<O:P> 
            </O:P></SPAN></FONT></P>
            <P class=MsoNormal 
            style="MARGIN-TOP: 0px; MARGIN-BOTTOM: 0px; TEXT-INDENT: 21.75pt; LINE-HEIGHT: 150%"><FONT 
            face=宋体 color=#008080><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">这说明，该系统能在干扰输入功率电平比扩频信号功率电平高</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">22dB</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的范围内正常工作，也就是该系统能够在接收输入信噪比大于或等于－</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt">22dB</SPAN><SPAN 
            style="FONT-SIZE: 12pt; FONT-FAMILY: 宋体; mso-ascii-font-family: 'Times New Roman'; mso-hansi-font-family: 'Times New Roman'">的环境下正常工作。</SPAN><SPAN 
            lang=EN-US style="FONT-SIZE: 12pt"><SPAN 
            style="mso-spacerun: yes">&nbsp;</SPAN></SPAN></FONT></P></TD>
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