Predictive action power control scheme for a mobile satellite system

Mehta, M.; Nunn, D.; Braithwaite, S J

doi:10.1109/icupc.1996.562671

Cited by 4 publications

(2 citation statements)

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“…This implies that power control in S-UMTS aims at compensating the slow fading due to shadowing, while the effects of multipath are expected to be mitigated through interleaving and channel coding. Secondly, the effects of delays can be mitigated through adaptive prediction [8,14]. Basically, adaptive prediction uses data up to the present time to adjust parameters of the predictor so that past predictions closely match observed data.…”

Section: Introductionmentioning

confidence: 99%

A Comparative Study of Predictive Transmit Power Control Schemes for S-UMTS

2005

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Transmit power control is indispensable in Direct Sequence Code Division Multiple Access (DS/CDMA) based systems such as the Satellite Universal Mobile Telecommunication System (S-UMTS). Since S-UMTS aims at achieving close integration with the terrestrial component (T-UMTS) in its complementary role, it is going to implement closed-loop transmit power control (TPC) at a slow rate of once every frame. In addition, predictive schemes can be used to mitigate the effects of delay. In this regard, recursive-least-squares (RLS) and least-mean-square (LMS) algorithms are normally employed. The RLS algorithm has a higher convergence rate than the LMS algorithm: an attractive attribute when the fading process abruptly changes. The LMS algorithm, on the other hand, has better tracking property than the RLS algorithm: an attractive attribute when the changes in the fading process are persistently slow. However, the mobile satellite system channel exhibits both attributes: abrupt changes and slow drifts. In this paper, therefore, we compare the performance of predictive TPC based on the RLS and the LMS algorithms for S-UMTS with the conventional TPC as a reference. We demonstrate that the predictive TPC schemes perform better than the conventional TPC scheme. However, the performance gain achieved depends on the predictive algorithm used, the environment in which the user equipment is operating, and loop delays. We show that, in general, the LMS based predictive TPC offers better performance than the RLS based predictive TPC scheme in S-UMTS environment.

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Section: Introductionmentioning

confidence: 99%

A Comparative Study of Predictive Transmit Power Control Schemes for S-UMTS

2005

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“…More provides both data secrecy and data reliability in one process to advanced schemes were subsequently proposed based on deal with the problems in an insecure and unreliable channel. adaptation of data transmit system in accordance to the Using error-correcting codes as cryposystems was introduced environmental conditions variations [14][15][16][17]. In [18], one 1-4244-1057-6/07/$25.OO ©2007 IEEE.…”

Section: Introductionmentioning

confidence: 99%

A Secure Channel Coding Scheme for Efficient Transmission of Remote Sensing Data over the LEO Satellite Channels

Payandeh

Ahmadian

Aref

2007

2007 3rd International Conference on Recent Advances in Space Technologies

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Both secure and error control coding are very by McEliece [6]. The McEliece proposal was to use a Goppa extensive subjects, each with a variety of sub-disciplines. In this code as the underlying basis of an ingenious public-key paper, we develop a secure channel coding (joint encryption-scheme. The security of this scheme is based on the well channel coding) scheme based on concatenated turbo codes for known NP-completeness of the decoding problem for general more efficient and secure transmission of the LEO satellite data. linear codes [7] and the fact that there are a huge number of Reliability and security are achieved by adapting the pseudorandom puncturing strategy with the change of distance between inequivalen codes with d g nset rametr Some satellite and ground station in the communication se'ance, to issue other public-key cryptosystems based on algebraic linear codes further burdened by reducing energy consumption or increasing are proposed in [8][9][10][11]. It is well-known that public-key bit rate of data transmission. Simulation results show the cryptosystems can be used as private-key cryptosystems.relevance and superior performance of the proposed scheme Therefore, Rao and Nam [12] proposed to modify the McEliece compared with the traditional data transmission system. scheme and subsequently introduced a new approach to the

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