hiiiiiii
it could be a silly question for, but I am an electronics engineer, and recently I am a trainee in commnications..
i wanna to ask why the BER must be less than -110dbm?? i.e why the sum of errors in bins 5,6and 7 must be less than errors in bin_0 ??? that’s my question…
regards
i don’t understand your question, but the BER is a rate (in percentage), and “-110 dBm” is a measured power, in decibel-milliwatt. So the BER cannot be compared with dBm.
downlink and uplink had to use different bands, so one of them had to be higher and the other lower. I don’t think there is a logical explanation for it. It’s random…
Some might say that uplink on the lower band allows a better radio propagation (low freq propagates better than high freq).
Yet, the benefit is about 0.5dB, as far as i recall… neglictible !!
because higher frequency has more large pathloss than lower frequency, BTS(nodeB) has a larger output power than MS(UE).so
down link frequency is higher then up link frequency.
I think the reason behind it is lower freq. has a large wavelength than the higher freq.so it can travel large area with low power(as in MS)compaired to BTS.
Uplink frequencies in mobile systems are always the lower band of frequencies, because it requires less power to transmit a lower frequency over a given distance and this saves valuable power of the MSs