A received binary NRZ signal assumes the voltage levels of 500 mill volts and -500milli- volts respectively for ‘1’ and ‘0’ transmission with a bit rate or

r bits/second. The signal is corrupted by additive white Gaussian noise with a two sided spectral density of
.

The received signal is processed by an integrate and Dump circuit in every bit interval and compared with a zero threshold to take a bit decision.

Assuming ‘1’ and ‘0’ transmission to be equally likely, determine the maximum value of r such that the bit error probability  

Given          at x = 4.27

erfc         at x = 3.02