Multipath communication channels

Part 2 book "Fundamentals of communication systems" includes content: Multidimensional digital modulation, digital transmission through bandlimited AWNG channels, multicarrier modulation and OFDM, an introduction to information theory, coding for reliable communications, data transmission in fading multipath channels, spread spectrum communication systems.

419p muasambanhan06 03-02-2024 5 2   Download

An image transmission underwater communications system has been researched and developed during the past years due to its potential applications in life, military, oil exploitation, and transportation. In this brief report, a study on the effect of the modulation method on the image communication through the underwater acoustic channel was performed.

9p vifriedrich 06-09-2023 6 4   Download

In chaos-based digital communications, the differential chaos-shift keying (DCSK) system has been widely studied owing to its non-coherent demodulation without any synchronization. To date, BER performance of this system is investigated over various transmission channels such as noise, fading, multipath, and optical fiber. In this paper, for the first time, the BER performance of conventional DCSK system is evaluated over a land mobile satellite channel.

5p vispyker 16-11-2022 14 3   Download

The Jaccard index was used to determine the new method’s accuracy performance. The results showed a significant improvement in the clustering of the developed algorithm than the standard K-PowerMeans. The results showed a significant improvement in the clustering of the developed algorithm than the standard K-PowerMeans.

23p spiritedaway36 28-11-2021 25 5   Download

The LMS algorithm is known as a simple algorithm, which is fast computation time and the computation results are quite satisfying. In this study, the authors used Simulink software on Matlab. In general, this research is divided into three stages, namely modeling multipaths communication channels as an adaptive system, designing an adaptive system model on Simulink, and designing a simulation of 250 iterations.

7p lucastanguyen 28-05-2020 6 0   Download

The mobile radio propagation environment clearly places fundamental limitations on the performance of radio communication systems. Signals arrive at a receiver via a scattering mechanism, and the existence of multiple propagation paths (multipath) with di€erent time delays, attenuations and phases gives rise to a highly complex, time-varying transmission channel. In order for systems engineers to determine optimum methods of mitigating the impairments caused by multipath propagation, it is essential that the transmission channel be properly characterised. ...

26p tienvovan 16-09-2010 86 7   Download

Characterisation of Multipath Phenomena In Chapter 3 we described some methods for predicting path losses, concentrating on those applicable to mobile communication systems. The discussion centred around techniques that deal principally with radio propagation over irregular terrain; methods of predicting signal strength in urban areas or in other environments, e.g. inside buildings, were deliberately left until Chapter 4. These propagation models are extremely important since the vast majority of mobile communication systems operate in and around centres of population....

50p tienvovan 16-09-2010 61 6   Download

Parametrization – a Technique for SDR Implementation Friedrich Jondral University of Karlsruhe Mobile communications is mainly a service driven business. But there are important marginal conditions from physics and technology that may not be ignored when developing a mobile communications system; the frequency spectrum is a scarce resource. Therefore terminals, mobile as well as base station transceivers, have to work efficiently with respect to spectrum. Mobile radio channels are complicated due to multipath propagation, reflections, scattering, time, or frequency dispersion, etc. ...

24p vaseline 30-08-2010 91 12   Download

Additional Techniques for Capacity and Flexibility Enhancement As shown in Chapter 1, wireless channels suffer from attenuation due to the destructive addition of multipath propagation paths and interference. Severe attenuation makes it difficult for the receiver to detect the transmitted signal unless some additional, lessattenuated replica of the transmitted signal are provided. This principle is called diversity and it is the most important factor in achieving reliable communications.

29p huggoo 20-08-2010 90 6   Download

Examples of Multipath Fading Channels As discussed, when a signal is transmitted through a multipath fading channel, a channel model, which we assume, gives its received characteristics. For instance, the p.d.f. such as Rayleigh distribution and Ricean distribution describes the envelope fluctuation for an individual multipath component in the channel, the multipath intensity profile or spaced-frequency correlation function determines the frequency selectivity of the channel, and the Doppler power spectrum or spaced-time correlation function determines the time selectivity of the channel.

10p khinhkha 20-07-2010 91 16   Download

As we step forward into the new millennium with wireless technologies leading the way in which we communicate, it becomes increasingly clear that the dominant consideration in the design of systems employing such technologies will be their ability to perform with adequate margin over a channel perturbed by a host of impairments not the least of which is multipath fading.

40p khinhkha 20-07-2010 61 11   Download