Modulation Rates

How do Modulation Rates Impact Wireless Communication?

Modulation rates simply outline how many bits per symbol per transmission you can achieve.

The more bits that can be represented by a symbol, the more data that can be transferred across your network.

The result of using higher orders of modulation is a greater return on investment in your network equipment and spectrum.

In the past, radio transmission was slow in terms of the number of bits per symbol being transmitted – this was transmission at lower orders of modulation.  Technological advancements in recent years have sped up the transmission significantly to create much higher orders of modulation.  Unique in narrowband channels, Ubiik Mimomax provides 256QAM which provides 8 bits per symbol in our Tornado radios.    

One aspect of modulation to consider is that the higher modulation rate you use, the greater your susceptibility to noise or interference.  You can therefore only achieve successful transmission (without increasing your bit error rate) at higher orders of modulation if your equipment has been designed to mitigate interference.   

Still need further explanation?

As an example, imagine sending a morse code signal with a flashlight across a bay to someone on the other side.  If you flash the code slowly (lower order modulation), chances are good that the recipient will get the message.  If you flash the code rapidly (higher order modulation), it will be harder for the recipient to receive the message without making mistakes as you increase your speed.   

In this scenario, for transmission to be successful at the higher rate, you would require the recipient to have precision skills in order to receive and transcribe the message.  The same situation applies within the world of radio – to operate at higher orders of modulation requires a level of precision in the design and manufacture of the radios to provide high immunity to noise and interference.  

Bits per Symbol – QPSK, 16QAM, 64QAM, 256QAM

Below are the bits per symbol that can be achieved at various rates of modulation.

Keen to read more?

Find out about how Adaptive Modulation works here.