Receiver gain planning for spread spectrum/low SNR system

Status
Not open for further replies.

Ghost Tweaker

Member level 5
Joined
Nov 11, 2003
Messages
94
Helped
2
Reputation
4
Reaction score
2
Trophy points
1,288
Activity points
980
Hi everone,

I was wondering how one defines the required gain for a receiver when the signal SNR is negative, which is the case for example for spread spectrum coms.

My current understanding is that knowing the system bandwidth, one can determine the noise power at the system input. Then knowing the ADC full scale range, the gain can be determined as the gain required to bring the noise power at the input of the receiver up to the full-scale range. Is it the right approach?

Then what about the required gain range? The signal power may vary but the thermal noise power stays constant. Does it mean that, if we neglect interferers and the thermal noise is considered constant, the gain can be constant an no VGA is required. Please comment...

Regards
Ghost Tweaker
 

Status
Not open for further replies.

Similar threads

Cookies are required to use this site. You must accept them to continue using the site. Learn more…