Autonomous position determination in the Globalstar satellite communication system is discussed. ( ) The two-way communication between a user terminal on the earth’s surface and a single low earth orbit LEO satellite makes it possible to derive range and range-rate and determine the user terminal position instantly. Expected accuracy is presented, and a simple direct solution is given. INTRODUC...

Ultra small scale satellites have a very demanding and limited mass and power budget specification; therefore, mostly the design constraints prevent the use of small scale camera. In this paper, an imaging capturing subsystem is proposed for ultra small satellite, which includes low power consumption components; the developed imaging capturing subsystem was studied, simulated and successfully i...

This work is aimed at investigating the use of Multi Carrier CDMA (MC-CDMA) techniques in variable bitrate transmission over low-earth-orbit (LEO) satellite channels by means of realistic simulations. It is known by literature that MC-CDMA techniques are much more resilient with respect to multi-user interference effects in multipath fading channels than single-carrier DS/CDMA ones. Moreover, M...

The problem of handoffs in cellular networks is compounded in a low earth orbit (LEO) satellite-based cellular network due to the relative motion of the satellites with respect to a stationary observer on earth. Typically, the velocity of motion of mobiles can be ignored when compared to the very high velocity of the footprints of satellites. We exploit this property of LEO satellite systems an...

This paper evaluates the proposed implementation of short length low density parity check (LDPC) codes within the telemetry space protocol. Due to the varying orbital patterns of low earth orbit (LEO) satellites, limited communication time windows need to be optimised to maximise data throughput. Most popular connection oriented protocols focus on correcting congestion related link errors, but ...

Low-Earth Orbit (LEO) satellite systems are intended to have an important part of the future generation of mobile telecommunication systems. They aim to provide di erent services to various populations of users. Each class of users requires a certain Quality of Service (QoS) and thus a given part of the shared channel resource. In this paper, LEO satellite systems based on an earthxed cell conc...

Satellite network, especially low earth orbit (LEO) satellite network, which has advantages of global coverage and short round-trip time (RTT), has played an increasingly important role in the future generation of global communication network. Due to fast velocity, frequent handover and time-varying topology, designing effective routing algorithm for LEO satellite network has always been challe...

With the rise of a new generation low Earth orbit (LEO) satellite constellations and advancement 6G network, satellite–terrestrial integrated Internet Things (IoT) in future will achieve global coverage through integration LEO constellation, extend computing to edge network deployment services constellation so as meet demand mass connection latency data processing. The be an cloud combining com...

Future satellite communication systems proposed use geosynchronous (GEO) satellites, medium earth orbit (MEO), and low earth orbit (LEO) constellations with fast packet switching and quality of service (QoS) provisioning. In this paper, we present broadband GEO, MEO and LEO satellite network QoS models and simulated performance results. This paper proposes a new method of bandwidth allocation d...

Adaptive modulation is a powerful technique to improve the energy efficiency and increases the data rate over a fading channel. The ground station transmitter and the satellite receiver adapt the modulation scheme and the transmitter power to the state of the channel. In this paper, we study adaptive multi-level quadrature amplitude modulation (M-QAM) schemes for LEO satellite over a Rayleigh f...