Performing Digital Bit Error Rate Measurements
应用文章
Introduction
Verifying Bit Error Rate (BER) performance can present a real challenge to RF engineers. RF engineers designing RF receivers may not have access to the baseband functionality required to perform coded BER measurements, which can present a barrier to verifying coded BER - a key receiver design specification with today’s digital communications signal formats.
Some systems also have Digital-to-Analog (D/A) converter(s) at the transmitter input and Analog-to-Digital (A/D) converter(s) at the RF receiver output, which add additional complexity in evaluating RF performance metrics such as EVM along the RF transmitter and receiver chain.
Lastly, because BER is an end-to-end metric, it may be desirable to perform digital-IF/RF-digital BER verification by generating a digital stimulus for the D/A converters on the transmitter and capturing the digital output of the receiver after the signal has been digitized with A/D converters. This would allow the entire transmit-receive path to be verified from digital bits in to digital bits out, including the IF/RF and RF/IF upconverters and downconverters.