The BGAN Modem Subsystem (BMS) provides software PHY functionality for an Inmarsat BGAN terminal. The BMS in concert with a customer-furnished protocol stack implements the complete Access Stratum of the IAI-2 air interface (the BGAN waveform).
The BGAN Modem Subsystem is comprised of:
BGAN Decoding Subsystem (BDS) for baseline, BGAN-X and LDR/HDR bearers
BGAN Forward Demodulator Subsystem (BFDS) for baseline, BGAN-X and LDR/HDR bearers
BGAN Return Modulation Subsystem (BRMS) for baseline, BGAN-X and LDR/HDR bearers
BGAN software Turbo decoder or FPGA Turbo decoder interface
Real-time framework with OS abstraction layer
Modem application
The BPLT/UT Interface (BUI) functional block, which is required in order to interface to the BPLT when running the UT physical layer Mandatory Test Requirement scripts (UTMTRs), is also available.
The BFDS is operational in SwiftBroadband (SBB) UTs from several vendors. The BMS is undergoing final type approval testing in an SB-SAT UT, which will be deployed in-orbit on a range of satellite platforms. (More)
Specifications
Downloads
Features
Complete Inmarsat BGAN UT modem subsystem (except Turbo decoder, available separately)
Derived from SPCI’s “Gold Brick” BGAN Physical Layer Tester (BPLT)
Available with support for UT Classes 1, 2 & 3 (Land transportable), 8, 9 & 14 (Maritime), 10 & 11 (Land mobile) and 6, 7 & 15 (Aeronautical).
Equalizer available for Aeronautical Classes
Meets all Inmarsat transmitter and receiver specifications
Easily integrated with BGAN protocol stack
C++ fixed-point software implementation
Configurable frequency acquisition range
Internal code rate AVP detection and handling
Demodulator statistics available to application
Supported Platforms
TMS320C64x, C64x+, C6727
Readily customizable for other platforms
Performance Highlights
Meets all Inmarsat PER specs, margin > 0.25 dB
Compliant acquisition and recovery from blockage
Fast global bearer acquisition (PER ? 1e-3 within 5 frames over ±2kHz)
Compliant code rate detection and misidentification performance
Compliant C/No estimation
Large dynamic range demodulator typically removes need for hardware receiver AGC
DSP Requirements
Compatible with 330 MHz C64x+
2 MB external RAM (alternatives available for reduced external RAM)
Internal RAM required is dependent on DSP cache but nominally 128 kB
