Amplitude Modulation Archives

20 04, 2016

RF Measurements in the Cable Plant

Mia Colabrese2021-08-16T20:15:37-04:00April 20th, 2016|

RF Measurements in the Cable Plant - Learn more about RF Episode 20 Hosted by Brady Volpe of the Volpe Firm and Nimble This. Guest John Downey, CMTS Technical Leader at Cisco Systems and special guest, Ron Hranac Technical Leader at Cisco Systems. Today’s show we will cover a number of topics including RF measurements and fundamentals. The discussion starts with basic building blocks of the sine wave and evolves to how QAM (quadrature amplitude modulation) signals are comprised of sine waves with varying amplitude and phase shifts, which means even though we call

DOCSIS 3.0 Tutorial – The EQAM

Mia Colabrese2021-08-17T15:58:05-04:00July 1st, 2010|

In my article on DOCSIS 3.0 M-CMTS architecture, I talked about the distributed nature of the CMTS with an M-CMTS core (the CPU of the system), a DOCSIS Timing Server, and an edge Quadrature Amplitude Modulator (EQAM). I am going to cover the EQAM in detail in this article because in the past couple of years, EQAM (also spelled eQAM) has rapidly become part of our vocabulary but its operation and value often go unappreciated. Further, in order to fully understand DOCSIS 3.0 operation, downstream channel bonding, and possible issue which may arise, a thorough understanding of the eQAM is critical.

DOCSIS and Cable Modems – How it works :: Advanced RF

Mia Colabrese2021-08-17T13:36:52-04:00February 2nd, 2009|

In high speed data communications, the industry has evolved and implemented complex modulation schemes which vary a signals voltage (amplitude), phase, and frequency in order to transmit more data, faster. The following will cover these methods in order to describe how Quadrature Amplitude Modulation (QAM) works in DOCSIS communications. We live in an analog world. Sure, [...]