relation between ebno and snr

hi ,i am trying to find relation between ebno and snr and intrepret the equations.how to understand this relation in analog and digital domains?Is it same intrepretation in both analog and digital domains.In matlab i found the relation between ebno and snr is
esno = 10log(Tsym/Tsam) + snr ,and why they are using bandwidth of noise =sampling factor.

if that is the case , for me 1 sym = 1 bit. Tsym/Tsamp = 30. so that sampling factor comes around 14 db and if my algorithm is working at ebno of 18db for ber 1e-6 then from the above equation i calculated snr as 4 db .Is the correct way am i am intrepreting or wrong please help me in this? If it is true in practical what i observed is by using noise com ber meter tool if i set ebno as 18 db i am observing snr same 18 db in spectrum analyser then what is the difference between practical and simulation in matlab.
In practical ebno = 10log(rb/bandwidth of noise) +snr.
so please help me in this.

SNR is defined as the signal power over noise power. For an AWGN with PSD N_0, the noise power is WN_0. So:

\[SNR=P/(W\,N_0)=(P/W)/N_0=PT_b/N_0=E_b/N_0\],

PT_b=E_b, and W~1/T_b for rectangular pulse signal.