Generic selectors
Exact matches only
Search in title
Search in content

BER

Viewing 15 posts - 1 through 15 (of 18 total)
  • Author
    Posts
  • #49658 Reply
    dana
    Guest

    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

    #49659 Reply
    pix
    Guest

    hi dana,

    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.

    Regarding the bins, i don’t know.

    regards,

    #49660 Reply
    dana
    Guest

    thank alot..
    I know my error..
    regards..

    #49661 Reply
    ashish tewari
    Guest

    hi, can any one please explain me

    why down link frequency is higher then up link frequency……

    #49662 Reply
    pix
    Guest

    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 !!

    #49663 Reply
    liujun
    Guest

    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.

    #49664 Reply
    pix
    Guest

    liujun : neglictible !

    #49665 Reply
    liujun
    Guest

    what’s mean about neglictible.

    #49666 Reply
    pix
    Guest

    the gain of pathloss between ul and dl is very small : it is not useful in real life !

    that’s what I mean with “neglictible”. But that’s just my opinion…

    #49667 Reply
    liujun
    Guest

    up link coverage limted in GSM/UMTS commercial network sometime will be occured.

    #49668 Reply
    pix
    Guest

    yes, most of GSM sites are uplink limited, you are right.

    –> The benefit of the uplink band being lower than the downlink band is not useful…

    #49669 Reply
    liujun
    Guest

    thanks. may be the frequence question of UL and DL need to be solved by RF equpment designer. hehe.

    #49670 Reply
    ami
    Guest

    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.

    #49671 Reply
    pix
    Guest

    Ami, I am very very sad you
    didn’t
    read
    the
    previous
    posts…

    #49672 Reply
    telecom72
    Guest

    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

Viewing 15 posts - 1 through 15 (of 18 total)
Reply To: BER
Your information:




<a href="" title="" rel="" target=""> <blockquote cite=""> <code> <pre class=""> <em> <strong> <del datetime="" cite=""> <ins datetime="" cite=""> <ul> <ol start=""> <li> <img src="" border="" alt="" height="" width="">