Digital communication systems

Digital signals are represented by binary numbers: 1 or 0. The 1 and 0 values can correspond to different discrete voltage values. Any signal that doesn’t quite fit into the scheme is rounded off. By using a binary signal, error correctionembedded signaling and control bits are possible in each packet transmitted. A packet contains an assembly of bits. The software contains an algorithm that understands the differences between voice and background noise, and in return, cancels the unwanted background noise and unwanted audio. The wireless digital signal provides the same levels of reliability and control as a wired digital signal.

The advantages of digital two-way systems include:

• Information such as unit ID, status buttons, and enhanced text messages can be embedded into a single digital radio channel.
• Bandwidth consumption is reduced. (Resulting in a lower BIPT license fee in Belgium)
• Digital signals can be handled by standardized (existing) antenna systems.
• The digital conversion of a user’s voice reduces external background noises.
• A number of new software applications are available for use with the digital platform. (e.g. for GPS)
• The digital platform provides a migration path that allows the use of digital radio's in analog mode.
• The digital signal will stay strong and clear to the limits of coverage. (by contrast, analog audio will slowly fade out until it is unrecognizable)

The disadvantages of digital two-way systems include:

• Due to the additional features and enhanced functionality, a learning curve exists for first-time users.
• Digital signals are intolerant to radio frequency (RF) noises, and in the presence of too much RF noise, the signal can result in an error.

Kenwood NEXEDGE digitaal

NEXEDGE uses advanced DSP (Digital Signal Processing) technology for voice transmission. It supports both analogue FM and digital NXDN communication, and the system can be extended by simply adding base stations.

With NEXEDGE, Kenwood offers a turn-key solution with exceptional digital features suited for secure communication, particularly for corporate and governmental entities.

The underlying digital NXDN technology offers more functions and improved efficiency compared to current PMR devices. NEXEDGE currently uses existing VHF and UHF frequencies for mobile land communication, but the 6.25 KHz channel spacing allows for an increase of twice the number of communication channels in a frequency band of 12,5 KHz. Eventually, digital systems will replace conventional analogue radio communication devices.