As for what you have asked about the global parameters, I will give a quick explanation:
– sequence length: the number of data bits to be transmitted.
– samples per bit: the number of samples that the software makes in vector and matrix calculations. for example, if your bitrate is 10e9gbps and you have two samples per bit, the your sampling rate is 20e9.
– number of samples: allow me to exemplify: if you have a sequence of length N and your samples per bit is set to M, then the number of samples equals: M x N .
– symbol rate: I think it refers to the type of data coding you use. If you are using 4-qam, for example, your symbol rate is half the amount of your bit rate.
I hope this helps.