已知加性高斯白噪聲(AWGN,Add itiveWhite Gaussian Noise)信道,信號的帶寬范圍為300~3400Hz,信號與噪聲功率比為26dB, (1)計(jì)算該信道的最大信息傳輸速率; (2)若信號與噪聲功率比降到10dB,且保持信道最大信息傳輸速率不變,則信道帶寬應(yīng)該變?yōu)槎嗌伲?/p>
某離散無記憶信源符號集為,所對應(yīng)的概率分別為:0.4,0.2,0.1,0.1,0.07,0.05,0.05,0.02,0.01,碼符號集為{0,1,2,3}. 1)求信源的熵H(X)及信源剩余度γ; 2)對其進(jìn)行四元Huffman編碼; 3)求平均碼長,編碼效率η及編碼器輸出的信息傳輸率(碼率)R.
設(shè)有一離散信道,其信道矩陣為,求 (1)最佳概率分布? (2)當(dāng)P(x1)=0.7,P(x2)=0.3時,求平均互信息I(X;Y)和信道疑義度H(X/Y); (3)輸入為等概分布時,試寫出一譯碼規(guī)則,使平均譯碼錯誤率pE最小,并求此pE.