Homepage - RF Cafe
Webmaster: Kirt Blattenberger | KB3UON | Sitemap | ©1996-2014
Menu below is just a small sample of what is here!
 
Custom Search
More than 10,000 searchable pages indexed.
•−•  ••−•    −•−•  •−  ••−•  •
RF Cafe Morse Code >Hear It<

Bit Error Rate

Bit error rate (BER) is used in digital telecommunication as a figure of merit for how effectively the receiver is able to decode transmitted data. It is the percentage of bits that have errors relative to the total number of bits received in a transmission, usually expressed as ten to a negative power. For example, a transmission might have a BER of 10-5, meaning that on average, 1 out of every of 100,000 bits transmitted exhibits an error. The BER is an indication of how often a packet or other data unit has to be retransmitted because of an error. If the BER is higher than typically expected for the system, it may indicate that a slower data rate would actually improve overall transmission time for a given amount of transmitted data since the BER might be reduced, lowering the number of packets that had to be resent.

A common example of this is with a dial-up modem connection to an ISP (for those remaining who do not have broadband, or at least can remember the bad old days). During the initialization sequence when communications are being established between the computer modem and the ISP modem, it was possible to hear the digital noise. An arbitration process ensued whereby the highest data rate is attempted and if it resulted in too high of a BER, the modems mutually agreed to drop back to a lower rate. The process continued until an acceptable BER was achieved. That is why sometimes you would get a 50,2 kB connection, while at other times you might get only a 24.6 kB connection. In my own experience, the lower data rates were almost a certainty when it was raining; evidently poor insulation somewhere in the telephone lines allowed enough current leakage between conductors, or degraded poor connections enough to cause significantly higher noise.

A BERT (bit error rate test or tester) is a procedure or device that measures the BER for a given transmission.
Bit error rate (BER) equation
when added noise level approaches noise floor of receiver:
Bit error rate (BER) equation
where:    fb = transmission bit rate
N0 = noise spectral density (dBm/Hz)
Ni = injected noise spectral density (mW/Hz)
Eb = energy per bit (dBm/Hz)
C = carrier power (dBm)
T = ambient temperature (K)
k = Boltzmann's constant = 1.380 x 10-23 (J/K)
F = noise factor at injection point of receiver
 
A Disruptive Web Presence

Custom Search
Over 10,000 pages indexed! (none duped or pirated)

Read About RF Cafe
Webmaster: Kirt Blattenberger
    KB3UON

RF Cafe Software

RF Cascade Workbook
RF Cascade Workbook is a very extensive system cascaded component Excel workbook that includes the standard Gain, NF, IP2, IP3, Psat calculations, input & output VSWR, noise BW, min/max tolerance, DC power cauculations, graphing of all RF parameters, and has a graphical block diagram tool. An extensive User's Guide is also included. - Only $35.
RF system analysis including
frequency conversion & filters

RF & EE Symbols Word
RF Stencils for Visio

Product & Service Directory
Personally Selected Manufacturers
RF Cafe T-Shirts & Mugs

RF Cafe Software

Calculator Workbook
RF Workbench
Smith Chart™ for Visio
Smith Chart™ for Excel
Your RF Cafe Progenitor & Webmaster
Click here to read about RF CafeKirt Blattenberger... single-handedly redefining what an
                                 engineering website should be.

View the YouTube RF Cafe Intro Video Carpe Diem! (Seize the Day!)

5CCG (5th MOB): My USAF radar shop

Airplanes and Rockets: My personal hobby website

Equine Kingdom: My daughter Sally's horse riding website