Abstract: Modern receiving systems must often process very weak signals, but the noise added by the system components tends to obscure those very weak signals. In this study, a novel noise measurement technique using the Agilent ESG-D series RF signal generators provide an optional internal BER analyzer (Option UN7) is proposed. This technique offers generic BER analysis capabilities for demodulated PN9 and PN15 data sequences that meet ITU-T standards. Also, the study presents the techniques which relate the BER to the noise figure of the system and BER with Minimum Detectable Radiated Power Density (MDRPD).