Digital Satellite Modems
|
Evaluation of IDR and IBS Modems
|
|
This contract involved the evaluation of IDR and IBS modems from different manufacturers for a Government customer, who then went on to purchase production quantities of the recommended modems. |
Design of Spread Spectrum Modems
|
|
Involvement in the design of various types of direct sequence spread spectrum modems, for Government customers. Some of these were for operation in CDMA systems. |
Design of a Variable Data Rate High Speed Burst-mode QPSK Modem
|
|
The design of this modem was for a Government customer. |
DSP-based 64 kBit/s Coded 8-Phase Modem
|
|
Involvement in the design and development of a DSP-based 64 kBit/s coded 8-phase modem, offering significantly greater SCPC traffic capacity than a conventional QPSK modem. |
INMARSAT Aeronautical Skyphone Modem
|
|
Involvement in the initial development and pre-production prototypes of the INMARSAT Aeronautical Service ground-based modems (for the BT Skyphone service). |
60 MBit/s QPSK/TDMA Modems
|
|
Performance evaluation and acceptance testing of 60 MBit/s QPSK/TDMA modems for the European Space Agency (ESA). The evaluations were carried out in satellite-loop, with and without various interfering signals. |
180 MBit/s QPSK/TDMA Modems
|
|
Performance evaluation and acceptance testing of 180 MBit/s QPSK/TDMA modems for the European Space Agency (ESA). The evaluations were carried out in satellite-loop, with and without various interfering signals. |
Optimisation of Modem Cover Filters
|
|
Optimisation (using computer simulation and measurements) of 180 MBit/s modulator and demodulator cover filters to minimise adjacent channel interference into carrier and clock recovery circuits. |
Optimisation of Modem Pulse Shaping Filters
|
|
Optimisation (using computer simulation and measurements) of the modem pulse shaping filters for the EUTELSAT ECS TDMA system. |
Study of Carrier and Clock Recovery Techniques
|
|
Study of carrier and clock recovery techniques for continuous-mode and burst-mode modems at 60 and 180 MBit/s. |
Modem Anti-Hangup Techniques
|
|
Investigation of anti hangup techniques for burst-mode demodulators, including the use of quenched filters. |
Design of a Special Purpose, 140 MBit/s Modem
|
|
Involvement in a contract to examine the feasibility of transmitting 140 MBit/s data over 72 MHz bandwidth satellite transponders. This involved considerable computer simulation, as well as the production of the subsystem specifications for the selected modulation & coding scheme. |
VSAT Modems
|
|
Involvement in the design and development of modems for VSAT applications.
See VSAT Systems.
|
Direct Sequence Spread Spectrum Simulator
|
|
Involvement in the design and development of a simulator for testing direct sequence spread spectrum demodulators. The unit generated typical spread spectrum signals with a choice of many types of coding. |