THALES Communications Les informations contenues dans ce document sont la propriété exclusive du Groupe THALES. Elles ne doivent pas être divulguées sans l'accord écrit de THALES Communications. 1/3 BSR-DAN-SIP-LRB (20-Aug-01) VDL2 to AM-DSB Interferences (1/3) > TRADITIONAL METHOD TO QUANTIFY A VOICE LINK DEGRADATION (S+N)/N Degradation > HOWEVER, IN THE CASE OF A VDL2 UNWANTED SIGNAL Short spurious pulses can be observed before the (S+N)/N degradation (at the very moment when the VDL2 transmission begins) These pulses are heared as "clocks" added to the voice Auditive discomfort depends on the repetiton cycle > SIGNAL/PULSE RATIO CHARACTERISTIC Definition of a "Signal/Pulse Ratio" S/P = 6 dB has been validated for VDL2 by AMCP WGB Various results according to the receiver type
THALES Communications Les informations contenues dans ce document sont la propriété exclusive du Groupe THALES. Elles ne doivent pas être divulguées sans l'accord écrit de THALES Communications. 2/3 BSR-DAN-SIP-LRB (20-Aug-01) VDL2 to AM-DSB Interferences (2/3) (for S/P=6dB)
THALES Communications Les informations contenues dans ce document sont la propriété exclusive du Groupe THALES. Elles ne doivent pas être divulguées sans l'accord écrit de THALES Communications. 3/3 BSR-DAN-SIP-LRB (20-Aug-01) VDL2 to AM-DSB Interferences (3/3) > TECHNICAL ANALYSIS TO EXPLAIN VARIOUS RESULTS ACCORDING TO THE VERSION Type 1 » Receiver front end is equipped with high signals protection » S/P results depend on the protection threshold adjustment Type 2 » equipped with an "interlocking system" » slight differences in front end adjustments > HOW CAN RESULTS BE IMPROVED ? Protection adjustment change for type 1 Then, same results as for type 2 This minor change has been validated (no impact on other characteristics)