Abstract: An additive white Gaussian noise (AWGN) generator for use in a communications system includes a microprocessor for determining a coefficient by multiplying a signal to noise ratio (SNR) with a value of a Gaussian density function, a memory device for storing the coefficient, a random number generator for generating N-bit address which is used to access a coefficient stored in the memory device, an adder for adding the coefficient accessed from the memory device by using the N-bit address to an input signal in a digital domain, and a digital/analog converter for converting a digital output of the adder into an analog signal. The AWGN generator shows flat frequency response at a slow symbol rate, e.g., a symbol rate of an input channel signal and, therefore, the channel signal and the AWGN signal may be added easily in the digital domain.

Abstract: In a monitoring system for testing a performance of a plurality of mobile communications terminals and networks, the monitoring system has a main body coupled with a plurality of mobile communications terminals through cables for transmitting DM data and data stream by using serial and USB interfacing with the mobile communications terminals, memory means for storing data collected by the main body, which is coupled with the main body and a data control unit for conducting an application software preinstalled therein to preset an operation schedule.