Product Manual

Product Manual for Tornado Radio Unit
16
3 TORNADO RADIO UNIT OVERVIEW
3.1 CONNECTORS
The image below shows each of the different connectors The Ethernet connectors are 10/100 Base-Tx connected
to a two-port switch (either port can be used). The operating input voltage range of the power supply is 10.5 to 64
VDC. The power supply must be able to supply at least 30 watts.
Warning: Do not power up the radio unit without a load (attenuator or antenna) connected to each of the N
connectors. Damage to the radio may occur otherwise.
Connectors
Each radio unit can operate as either a Base Radio Unit (BRU) or Remote Radio Unit (RRU) as part of a Multi-
point Digital Link (MDL) system or alternatively as a NDL unit as part of a Network Digital Link (NDL) system. The
actual mode of operation will depend on the Software Feature Enablers (SFEs) purchased and the product type
configured.
A MDL system consists of one BRU, tuned to one Tx/Rx frequency pair, with a number of RRUs, all tuned to the
corresponding, but opposite, Tx/Rx frequency pair. An NDL system consists of one ‘master’ NDL unit tuned to one
frequency pair with its corresponding ‘slave’ unit tuned to the opposite pair.
Mimomax Tornado radios consist of the following modules.
• Digital Processing System (DPS)
• Transceiver (TRCVR)
• Duplexers (DPLXR)
These modules are described in detail in the sections that follow.
User data (Ethernet or serial) passes from the various interfaces into the Digital Processing System (DPS) where
sophisticated processing takes place to code the data into a MIMO signal. This MIMO signal is created completely
digitally inside the DPS. The DPS then generates two signals at an IF frequency. There are two signals because
ultimately the signals will pass onto separate elements on the antenna. The Intermediate Frequency (IF) signals
are then passed on to the Transmitter module which mixes the signals up to the desired frequency and also
amplifies the signals to the required levels. The signals then pass through the duplexers. The duplexers are
special filters which prevent the transmitted signals from feeding back into the receiver module. Next the signals
are fed to the antenna.
The antenna is a special MIMO antenna which is able to transmit and receive on both the vertical and horizontal
polarisations at the same time. The MIMO antennas are essentially two antennas in one.
On the receive path, the radio signals are picked up by the MIMO antenna and fed through the duplexers and into
the receiver module. The receiver selects the radio frequency to receive and mixes this signal down to an IF. This
IF signal is then sampled by Analogue to Digital Converters (ADCs) on the DPS module. The DPS module then
performs very complex MIMO processing to decode the user data that was sent. This data is then passed to the
appropriate interface.