Question about ADC spec for wireless/wireline/telecomm.

[llci413]

I am currently research on ADC design which focus on communication. I have some question about the spec (SNR and bandwidth). it vary a lot form different design and application. i search in internet and have following summary:

Telecommunication (GSM,CDMA, WCDMA...)
the bandwidth and SNR/DR vary a lot for 2G ~3G application,
BW ~=200kHz~5MHz, SNR/DR~=10-bit~14 bit
reseach tend to multi-standard/reconfigable/low-power design.

Wireline communication (ADSL, VDSL...)
SNR/DR ~= 12~16 bit, BW~=1MHz~12MHz
reseach tend to increase BW.

Wireless communication (BuleTooth, Wi-fi...)
SNR/DR ~= 8~12 bit, BW~=1MHz~20MHz
reseach tend to increase DR to puch the ADC close to RF frond-end.

I am not sure they are correct. Please give me some opinion.
Thank you very much!

 

[Syukri]

First you must know there are different typre of ADC.

MOst common is the SAR ADC, which will cover up to 5Mbps with up to 16 bit resolution...

Other typre is like Pipeline ADC, Delta-SIgma ADC and flash ADC. All of this with differnt aspect..

well u may check their spec and then compare it to the application to know whether it's suitable or not

 

[electronics_kumar]

recommended SNR is 35dB for voice commn and 45dB for video commn

 

[llci413]

Thank for ur advices.

To Syukri,
Why SAR ADC is common for communication system?
I think it is not common for communication system in IP or SoC design.
Which kind of application u consider?

To electronics_kumar,
for voice, i think ADC SNR should be at least 60dB.
and for audio, it should be higher than 85dB.
for video comm, are u mean HDTV? is the bandwidth = 6MHz?

Thank you and Best Regards,
Louis

 

[Syukri]

I appologize for ur misunderstanding...Well for us who involved in IC Design, SAR ADC is the most useble ADC for electronic device application...

For communication, SAR is not so suitable...the resolution is moderate as well as the speed...

Generally in comm. system, the device involved must be fast enough to support ur high freqeuncy signal where resolution can be tolerate...

Pipeline ADC is usually applied in comm. and delta sigma ADC used in bio and medcal app. for the high resolution...

People now are going for a fast and high resolution ADC..it is quite tough to introduce this feature to our world...but we are working on it.

 

[xuedashun]

which structure do you use in your adc? delta-sigma??

I am currently research on ADC design which focus on communication. I have some question about the spec (SNR and bandwidth). it vary a lot form different design and application. i search in internet and have following summary:

Telecommunication (GSM,CDMA, WCDMA...)
the bandwidth and SNR/DR vary a lot for 2G ~3G application,
BW ~=200kHz~5MHz, SNR/DR~=10-bit~14 bit
reseach tend to multi-standard/reconfigable/low-power design.

Wireline communication (ADSL, VDSL...)
SNR/DR ~= 12~16 bit, BW~=1MHz~12MHz
reseach tend to increase BW.

Wireless communication (BuleTooth, Wi-fi...)
SNR/DR ~= 8~12 bit, BW~=1MHz~20MHz
reseach tend to increase DR to puch the ADC close to RF frond-end.

I am not sure they are correct. Please give me some opinion.
Thank you very much!

 

[llci413]

To xuedashun,

Yes, i am currently researching Discrete-Time MASH Sigma-delta modulator.
And i am looking for which kind of application (focus on communication)
is suitable for those architecture?
I am targeting spec:
60<SNR<90
1MHz<BW<20MHz.

Best Regards,
Louis