, , .
, /, . / C/N (dB) DVB-T . [2] / C/N . QPSK 1/2- C/N=3,1 dB, 16-QAM 3/4 - C/N=12,5 dB, 64-QAM 7/8 - C/N=20,1 dB.
, BER = 2∙104 .
DVB-T, , :
Ps min = F + 10log(kT0B)+C/N, (3.1)
:
Ps min (dBW);
F (dB);
k = 1,38∙10-23;
T0 = 290 K;
B (Hz);
C/N / (dB).
, :
Ps min (dBm) = 97,2 dBm + C/N. (3.2)
C/N : QPSK 1/2 Ps min = 94,1 dBm, 16-QAM 3/4 Ps min = 84,7 dBm, 64-QAM 7/8 Ps min = 77,1 dBm.
. , .3.5.
Rohde&Schwarz SFU, MPEG-4, DVB-T . /. , , . 3.6.
Rohde&Schwarz ETL.
. 3.5.
. 3.6.
Tektronix TDS2024B . .
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, DVB-T R&S SFU 1 dBm 50 dBm , .
, , BER . , , , . BER , , BER = 2∙104. , .
DVB-T , , (3.2).
(. 3.7), (. 3.8) , 18471.
. 3.7. I ( B2, B1, F)
.
, MPEG-4. DVB-T DVB-T (, , -) COFDM. , , .
. 3.8.
. BER . . , , , . . . .
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4. | IPTV |
4.1. IPTV
4.2.
4.3
4.4