It seems no one will reply.
jdac_18 wrote on Apr 1st, 2010, 12:05am:I have used the random bit generator, verilog 2 verilog 10 bit dacs, and sin and cos vsources.
What do you mean by "
verilog 2 verilog" ?
jdac_18 wrote on Apr 1st, 2010, 12:05am:1. What is the difference between the EVMQam in the calculator for transient analysis
and plotting real vs imaginary in envelope analysis?
Use capital letter and small letter correctly.
I can't understand what you want to mean at all ?
First of all, do you correctly understand results of Transient and Envelope Analyses of Cadence Spectre ?
For example, do you correctly understand "envlp_td" and "envlp_fd" ?
You can apply Ocean function, "
evmQAM()" for results of both Transient and Envelope Analyses.
Do you understand "Trajectory" and "Constellation" ?
If you use "
evmQAM()", you can calculate "EVM" and plot "Constellation".
http://www.designers-guide.org/Forum/YaBB.pl?num=1264511244But you can also plot "Trajectory" and "Constellation" without using "
evmQAM()".
I plot "Trajectory" and "Constellation" without using "
evmQpsk()" in the following.
http://www.designers-guide.org/Forum/YaBB.pl?num=1260978648jdac_18 wrote on Apr 1st, 2010, 12:05am:2. What do the parameters in the root raised cosine filter provided in the rfLib from Cadence mean?
I don't use Cadence Spectre for RF design. So I don't know what parameters are provided.
What component do you use in "rfLib" ? Some complex baseband signal generator including "Raised Cosine Filter" ?
What parameters are provided ?
jdac_18 wrote on Apr 1st, 2010, 12:05am:3. When I simulate using envelope analysis and look at the frequency output of the spectrum
I get a sinc function centered at zero with a bandwidth of twice the symbol rate.
It is a very natural result. Do you understand "Nyquist Transmission Theory" ?
http://en.wikipedia.org/wiki/Raised-cosine_filterjdac_18 wrote on Apr 1st, 2010, 12:05am:Should I filter using the SRRC to get -Rb/2 to Rb/2?
What purpose do you limit bandwidth to [-Rb/2, Rb/2] for ?
Don't you use complex baseband signal generator including "Raised Cosine Filter" from "rfLib" ?
Again do you understand "Nyquist Transmission Theory" ?