This paper first gave a brief introduction of communication channel models, and then describes the characteristics of the channel emulator. According to the characteristics of the channel model, multipath is a difficult problem for hardware implementation. In order to simplify the hardware, the polyphase filter can be used for multi-path delay. Then the paper reviews the polyphase filter in the...

Simulations of mobile radio systems require propagation models for determining the channel characteristics for a given arbitrary scenario. Propagation path loss models can be used to predict wireless channel characteristics like received signal strength, multipath effects, and interference. These predictions are an important aspect of simulation of wireless networks and aid in the high-level ne...

Effective identification of wireless channel in different scenarios or regions can solve the problems of multipath interference in process of wireless communication. In this paper, different characteristics of wireless channel are extracted based on the arrival time and received signal strength, such as the number of multipath, time delay and delay spread, to establish the feature vector set of...

We propose a finite impulse response (FIR) minimum mean squared error (MMSE) decision feedback equalizer (DFE) for orthogonal multipulse modulated signals received through a multipath channel. Our system model accounts for both the loss of orthogonality caused by the multipath channel as well as intersymbol interference (ISI). First, we review previous work on the subject which used the zero-fo...

We develop vector-sensor array processing to estimate the angles-of-arrival (AOAs) and time delays of multipath channels in the space-time-polarization domain. A MUSIC-type algorithm for joint angle and delay estimation with a vector-sensor array is derived. Potential applications include multipath channel estimation and mobile localization. Simulation results show that the space-time-polarizat...

Where f denotes Doppler Frequency, τ denotes multipath propagation delay, S (f,τ) denotes the scattering function. In a Power Delay Profile plot, the signal power of each multipath is plotted against their respective propagation delays. A sample power delay profile plot, shown below, indicates how a transmitted pulse gets received at the receiver with different signal strength as it travels thr...

time reversal (tir) technique is an effective and simple method for data transmission in extremely multipath indoor uwb channels that mitigates the complexity of receiver by its own time focusing feature. although, tir method has the suitable performance, but it is sensitive to the non-ideal channel estimation error. in this paper at first, the bit error probability of tir-uwb communication sys...

In this paper we consider noncoherent detection structures for multipath Ricean/Rayleigh fading channels. The multipath components are assumed to be unresolved, with known delays. These delays could have been estimated, for example, by using super-resolution techniques or sounding the channel with a wide-band pulse. We show that the Rayleigh channel optimum receiver (R OPT) consists of an “orth...

underwater target imaging using acoustic waves is possible by employing the method used in synthetic aperture radars. in recent years, synthetic aperture sonar has been the subject of several researches. wherein imaging of underwater moving target is required, inverse synthetic aperture sonar (isas) idea can be used but specifications and limitations of underwater channel should be considered. ...

In the mobile radio environment, signals are usually impaired by fading and multipath delay phenomenon. In such channels, severe fading of the signal amplitude and inter-symbol-interference (ISI) due to the frequency selectivity of the channel cause an unacceptable degradation of error performance. Orthogonal frequency division multiplexing (OFDM) is an efficient scheme to mitigate the effect o...