200KHz bandwidth each channel in GSM - how to achieve?
时间：04-08
整理：3721RD
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Hi all,
I am just wondering since P-GSM-900 network operates at 900MHz with transmit bandwidth 890.2–914.8MHz, each channel only have 200KHz bandwidth (since there are 125 channels).
How our cellphone can transmit such a narrow bandwith signal without interfering adjacent channel? For example my cellphone operates at channel 1, then there is another user nearby me operates at channel 2. With given such a narrow BW requirement, I think it is quite impossible to transmit high power with such a narrow BW.
Or the baseband will manage so that there wont be a channel number that is too close to your channel number?
Or there is such thing as super narow sinusoidal wave that can transmit at that particular narrow frequency BW?
Pls enlighten me..
I am just wondering since P-GSM-900 network operates at 900MHz with transmit bandwidth 890.2–914.8MHz, each channel only have 200KHz bandwidth (since there are 125 channels).
How our cellphone can transmit such a narrow bandwith signal without interfering adjacent channel? For example my cellphone operates at channel 1, then there is another user nearby me operates at channel 2. With given such a narrow BW requirement, I think it is quite impossible to transmit high power with such a narrow BW.
Or the baseband will manage so that there wont be a channel number that is too close to your channel number?
Or there is such thing as super narow sinusoidal wave that can transmit at that particular narrow frequency BW?
Pls enlighten me..
I wouldn't worry about that hkartadi. 200KHz in 900MHz is not technically challenging narrow in any sense. You can do a lot narrower than that, provided you keep the phase noise into proportion.