The environmental effects on
the received signal produce interference and impairments in the form of Bit Error
Rate (BER). BER is defined as the ratio of the number of incorrect bits
received versus the total number of bits. BER is estimated by the RBS on the
reverse-link and by the MS on the forward-link. IS-136 does not state
explicitly how the BER should be estimated but does specify the recommended
accuracy for BER estimations. BER measures the effects of radio
environment-introduced impairments which are discussed in the Speech Quality
and Link Budget documents in this RF module.
Bit error rates are reported in
Classes as shown in Table
The BER is estimated by
comparing the detected bits (after deinterleaving) with the decoded bits that
have been encoded. The BER Classes represent the BER before any forward error
correction takes place.