The Bit Error Rate (BER) is defined as the percentage of received bits in a particular time interval that have been altered through transmission
because of interference, noise, bit synchronization errors, or fading, distortion, or attenuation, to name a few of the most common causes. The rate is a ratio of
the number of bit errors divided by the total number of bits received. The BER is an approximate estimate of the bit error probability, but it is pretty
accurate over lengthy time intervals. For a detailed explanation and lots more information on BER, refer to the
Wikipedia article on this topic.
The Table below lists some common Bit Error Rates (BER) and Eb/No Requirements for Baseband
PCM Receivers. These Eb/No numbers are the BEST that can be achieved with IDEAL baseband
filtering and NRZ coding. To apply these numbers to BPSK or other modulation systems
requires that an "implementation factor" be added in. For instance, Ideal BPSK requires
8.4 dB for a BER of 1E-4. Please consult the appropriate communication theory textbooks
for further details, or check out some of the related links given below. Typical modulations
used for Spread Spectrum Systems will always require a higher Eb/No for a given BER than listed here!
