摘要:

AbstractA flexible, processor based, TDMA station has been implemented. This station and its associated variable data rate modem enables users to implement very complex frame structures under software control. Burst rates of 512 kb/s‐8‐192 Mb/s and different coding rates are possible allowing the transmitted bit energy from each station in the network to be adapted to prevailing conditions. The proposed application of the station is the transmission of mixed stream and packet traffic, in a LANs interconnection via satellite environment, using a modification of the FODA1technique. The association of the up‐link power control feature with the bit and coding rate variation gives the system an interesting ability to cope with fade conditions. The link outage probability is investigated for the Olympus transponder inkaband. The ability of the system, together with the good performance of Olympus, shows that theKaband is usable for the above mentioned types of networks without prohibitive fade degradation, at least for limited cove

ISSN:0737-2884    

DOI:10.1002/sat.4600100602

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractIn this paper we address the design of the data demodulator for high‐efficiency satellite communications suited for telemetry applications. We choose Gaussian minimum shift keying as the modulation format and analyse its relative merits with respect to the more traditional filtered offset quadrature phase‐shift keying scheme, when applied to medium‐to‐high data rate telemetry. Our study encompasses both geostationary orbits and the more challenging low earth orbit scenarios, and investigates the acquisition and tracking performance of the receiver with the aid of computer simulations. In particular, we present design criteria leading to the development of efficient, low‐complexity schemes for symbol timing and carrier phase/frequency recovery and we analyse the impact of these synchronization algorithms on the system performance. Next, we discuss the demodulator performance degradation when the transmitted signal is passed through on‐board solid‐state or travelling‐wave‐tube power amplifiers. The paper is concluded by a comparative analysis of the above modulation schemes, with special emphasis on their power and sp

ISSN:0737-2884    

DOI:10.1002/sat.4600100603

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

摘要:

AbstractThis paper deals with some problems of packet synchronization in a slotted packet‐radio communications system. The problems considered are bit‐synchronization and unique word detection for bursty systems. The necessary overhead for synchronization purposes is dimensioned for applications in land‐mobile satellite communication systems. The performance of synchronization is evaluated using hardware measurement equipment, including a commercial bit‐synchronizer. Using these results, the performance loss of communication systems due to packet synchronization effects can be estimated. This is done for the additive white Gaussian noise channel and the class of land‐mobile satellite

ISSN:0737-2884    

DOI:10.1002/sat.4600100604

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY

ISSN:0737-2884    

DOI:10.1002/sat.4600100601

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1992

数据来源: WILEY