Building GPS receiver chip

[nuntha]

Hi ,
I am intending to build a GPS receiver chip in CMOS. As I am not a good system guy I have a system question.

The GPS received signal is -130dBm
Receiver NF = 10 (upto last IF amp)
noise BW = 2MHz (before despreading)
Output SNR at the last IF amp is -23dB {inorder to acheive 20dB SNR after despreading as the coding gain is 43dB)

Hence knowing the output SNR of the last IF amplier is -23dB what is the ouput signal level at the last IF amplifier in dBm?

Thanks in advance

 

[brmadhukar]

Hi,
I was involved very much in GPS for OEM both at RF/System level.

You need to know that the ADC requires sufficient input signal strength for quantization. Only the noise should be able to trigger the quantization.
So get a "quote" for you ADC levels. Then you will be able to decide the overall gain.

BR
Madhukar