30 likes | 122 Views
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)
E N D
BSR-DAN-SIP-LRB 01.093 (20-Aug-01) • 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 • VDL2 to AM-DSB Interferences (1/3)
BSR-DAN-SIP-LRB 01.093 (20-Aug-01) (for S/P=6dB) • VDL2 to AM-DSB Interferences (2/3)
BSR-DAN-SIP-LRB 01.093 (20-Aug-01) • 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) • VDL2 to AM-DSB Interferences (3/3)