On Tue, 2008-06-10 at 23:24 -0700, alireza ghahremanian wrote: > Dear friends > > What is the relation between symbol rate and signal level, why when decrease the symbol rate the signal level increase ? > S/N = Es/No * Rs/B S = Received signal power (Watts) N = Noise power (Watts) Es = Average energy per symbol (Joules/symbol) No = Noise density (Watts/Hz) Rs = Symbol rate (Symbols/second) B = Bandwidth (Hz) For a particular BER, the receiver will require a certain Es/No. If S goes down, then Rs must go down (or B must go up) as well to maintain the same Es/No and hence the same BER. So in the case of lowering Rs and holding S/N the same, you are operating at a higher Es/No which means a lower BER. -Andy _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
