摘要:

AbstractThis paper presents experiences from the implementation of Multimedia Synchronization Mechanisms related to the support of the many‐to‐one inter‐media synchronization and describes the proposed Synchronization Architecture and its Design Objectives. The main goal of the communication system in the proposed architecture is to maintain the asynchrony levels between the media streams belonging in a Synchronization Group between the levels specitied by the Multimcdia Application. This is achieved through appropriate Synchronization Primitives related to the management and monitoring of the synchronization. The pilper emphasizes on the implementation issues and problems, and the solutions adopted. concluding to the lirst experiences from the use of the synchroniz

ISSN:1124-318X    

DOI:10.1002/ett.4460110302

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

年代:2000

数据来源: WILEY

摘要:

AbstractThe results of a computer search for convolutional encoders for the binary symmetric channel and the additive white Gaussian noise channel are reported. Both feed‐forward and feedback encoders are considered. It is shown that, when bit error rate is the design criterion. feedback encoders may outperform the best feed‐forward encoders at no additional complex

ISSN:1124-318X    

DOI:10.1002/ett.4460110303

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

年代:2000

数据来源: WILEY

摘要:

AbstractThe input‐output weight enumeration (distribution) function of the ensemble of serially concatenated turbo codes is derived, where the ensemble is generated by a uniform choice over the interleaver and a uniform choice of the component codes from the set of time varying recursive systematic convolutional codes. The conventional union bound is employed to obtain an upper bound on the bit error probability of the ensemble of serially concatenated turbo codes for the binary‐input additive white Gaussian noise (AWGN) channel with coherent detection OF antipodal signals and maximum likelihood decoding. The influence of the interleaver lengthNand the memory length of the component codesinon the ensemble performance is investigated and compared with relevant results for parallel concatenated multiple‐turbo

ISSN:1124-318X    

DOI:10.1002/ett.4460110304

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

年代:2000

数据来源: WILEY

摘要:

AbstractThe CDMA cellular system can provide more capacity than AMPS systems. To deploy microcells overlaying in macrocells to provide more capacity is also attractive. However, system performance and capacity degrade due to the co‐channel interference among microcells and macrocells if a single channel is used. Based on a hot‐spot overlaying environment. we propose three multi‐channel schemes where different channels can be assigned for hot spot and macrocell. Performance measures in terms of capacity, service hole, blocking probability and blocking ratio in uplink and downlink are evaluated. It shows that the schemes with channel selection based on SIR and active users gain more benefits than the scheme with separate channels assigned for macrocells and hot‐spot. Using the proposed multi‐channel access schemes, we can avoid the co‐channel interference among macrocells and hot‐spot and provide more capacities than Baier's suggestion [1]. In addition, the proposed schemes make soft handoff workable and improve the syste

ISSN:1124-318X    

DOI:10.1002/ett.4460110305

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

年代:2000

数据来源: WILEY

摘要:

AbstractThe problem of blind identification of digital communication channels from the second order cyclic and conjugate cyclic moments of the received signal is addressed. A novel condition for blind identification is obtained when both second order cyclic and conjugate cyclic moments of the received signal are available. In particular it is shown that the class of the identifable transmission channels is extended with respect to the case where only one of the two statistics is used.

ISSN:1124-318X    

DOI:10.1002/ett.4460110306

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

年代:2000

数据来源: WILEY

摘要:

AbstractRecently a steadily increasing interest towards usink the low voltage power distribution grid for various communication purposes is noticed. For the construction of appropriate equipment, being able to cope with the properties of such an unusual channel, a thorough understanding of physics is paramount. The work presented in the following describes essential contributions towards modelling basic properties of low voltage energy distribution networks as data channels. New and important measurement results of parameters significantly influencing the performance of communication systems are outlined. covering typical values and properties of network access impedance, propagation characteristics as well as different kinds of interference in the frequency range 20kHz to 150kHz. Furthermore channel model approaches based on the results are discussed.

ISSN:1124-318X    

DOI:10.1002/ett.4460110307

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

年代:2000

数据来源: WILEY

摘要:

AbstractIn this letter we present a general method for the computation of the outage probability in fading radio channels. It is based on the joint use of thesaddle‐point approximationand thegaussian quadrature rules. From our numerical results we have found that this procedure is fast and accurate at the same tim

ISSN:1124-318X    

DOI:10.1002/ett.4460110308

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

年代:2000

数据来源: WILEY

ISSN:1124-318X    

DOI:10.1002/ett.4460110309

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

年代:2000

数据来源: WILEY

ISSN:1124-318X    

DOI:10.1002/ett.4460110310

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

年代:2000

数据来源: WILEY

ISSN:1124-318X    

DOI:10.1002/ett.4460110311

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

年代:2000

数据来源: WILEY