13-06-2012, 03:54 PM
Air Ground Communication Focus Group Meeting
[attachment=24367]
Main B-VHF Facts
Broadband terrestrial cellular system based on multi-carrier technology
MC-CDMA for forward link (G/A)
OFDMA for reverse link (A/G)
High capacity/high performance integrated voice and data link system tailored for specific aeronautical needs
Supporting existing and emerging applications and services
OFDM, OFDMA and MC-CDMA are mature technologies
Proven by high-capacity bandwidth-efficient techniques, like DAB, DVB-T or W-LAN
COTS products are already available (MC-CDMA adopted proposal for 4G)
Most modern and spectrum efficient technology
Applicability of B-VHF
B-VHF as overlay system (options)
VHF band
Extended VHF band (COM+NAV+MIL)
DME band
B-VHF without overlay (options)
VHF (COM/NAV/MIL) band, free certain parts
DME band, use respective parts
MLS band for A-SMGCS applications
Sidelobe Suppression at Tx
Objective: Minimization of interference towards legacy VHF systems
Suppression to about -50 dB required
Sidelobe suppression techniques:
Deactivation of subcarriers (guard bands)
Suppression not satisfactory
Windowing
Suppression good, but not satisfactory
New approach: cancellation carriers
Laboratory Measurements
Measurements based on laboratory test-bed
The B-VHF signal covers the maximum frequency range symmetrical to the desired centre frequency of the DSB-AM receiver
System parameters
N_FFT = 128
B = 266.66 kHz
T_FRAME = 19.6 ms
Tx windowing
[attachment=24367]
Main B-VHF Facts
Broadband terrestrial cellular system based on multi-carrier technology
MC-CDMA for forward link (G/A)
OFDMA for reverse link (A/G)
High capacity/high performance integrated voice and data link system tailored for specific aeronautical needs
Supporting existing and emerging applications and services
OFDM, OFDMA and MC-CDMA are mature technologies
Proven by high-capacity bandwidth-efficient techniques, like DAB, DVB-T or W-LAN
COTS products are already available (MC-CDMA adopted proposal for 4G)
Most modern and spectrum efficient technology
Applicability of B-VHF
B-VHF as overlay system (options)
VHF band
Extended VHF band (COM+NAV+MIL)
DME band
B-VHF without overlay (options)
VHF (COM/NAV/MIL) band, free certain parts
DME band, use respective parts
MLS band for A-SMGCS applications
Sidelobe Suppression at Tx
Objective: Minimization of interference towards legacy VHF systems
Suppression to about -50 dB required
Sidelobe suppression techniques:
Deactivation of subcarriers (guard bands)
Suppression not satisfactory
Windowing
Suppression good, but not satisfactory
New approach: cancellation carriers
Laboratory Measurements
Measurements based on laboratory test-bed
The B-VHF signal covers the maximum frequency range symmetrical to the desired centre frequency of the DSB-AM receiver
System parameters
N_FFT = 128
B = 266.66 kHz
T_FRAME = 19.6 ms
Tx windowing