53
Twin-tuner principle
Two different, processed aerial signals are required
for the twin-tuner principle. This is achieved by means
of a spatial separation of the aerials and separate
amplification of the signals.
These aerial signals are used either as alternating or
individually or as a sum of both signals depending on
the reception quality.
This means that one of the two internal tuners is
responsible for the current reception of the station
being listened to while the other receives the
associated RDS data and simultaneously searches for
broadcasting stations with better reception quality in
the background. If it does find a better quality
reception, the two reception tuners swap roles. This
process is called switch diversity.
If the reception power as measured in decibels (dB)
falls below a certain value, both aerial signals are
used at the same time to obtain the station signals by
being adaptively combined. The aim is to create the
largest possible space between the station and
interference signal (interference voltage space).
This process is called phase diversity.
Furthermore a third tuner for receiving TMC
messages is permanently connected to one of the
aerial inputs. These messages are required for
dynamic navigation.
Tuner 1
Tuner 2
TMC
tuner
Signal converter
Demodulator 1
Demodulator 2
Radio Data
System 1
Radio Data
System 2
Na
v
m
o
dul
e
S397_099
Summary of Contents for RNS 510
Page 1: ......
