In this paper, we investigate multi user chirp spread spectrum with noncoherent detection as a continuation of our work on coherent detection. We derive the analytical bit error ratio (BER) expression for binary (BCSS) in presence multiple access interference (MAI) caused by correlation other signals because either asynchronism or Doppler shifts, both, and validate simulations. To achieve analy...

This algorithm uses the GPS satellite system for navigation. It is an innovative algorithm, because it employs only the Doppler measurements and starts with a known initial location of the receiver. Initially, this algorithm was developed for fixed point GPS transmitters. In the paper we have successfully attempted to adapt this algorithm for moving satellites. This algorithm appears to perform...

The two-dimensional patterns in our small angle neutron scattering (SANS) experiments from rapidly moving aerosols are anisotropic. To test the kinematic theory of two-body scattering that describes the anisotropy, we conducted SANS experiments using a constant source of D2O aerosol with droplets moving at approximately 440 m/s, and varied the neutron velocity from 267 to 800 m/s. The theoretic...

An adaptive Doppler-shift compensation scheme for wideband orthogonal frequency division multiplexing (OFDM) is proposed in this paper. This approach accommodates a time-varying Doppler, where the time scaling factor for each OFDM symbol is frequently estimated depending on the inherent periodicity of the cyclic-prefix and its preceding neighbours' values. The proposed technique relies on a sin...

Abstract. The Lorentz covariant theory of precise Doppler measurements (PDM) based on the retarded Liénard-Wiechert solution of the Einstein equations is described. An exact solution of equations of light propagation in the field of arbitrary moving bodies, which drastically extends the range of applicability of the new theory of PDM, is obtained. An explicit formula for the gravitational shift...

Dual-beam-scan Doppler optical coherence angiography (DB-OCA) with a 1-μm-wavelength probe is demonstrated for improved in vivo choroidal angiograms of the human eye. This method utilizes two scanning beams with spatial and temporal separation on the retina, and provides two measurable velocity ranges. The method achieves higher sensitivity to very low velocity flows than conventional Doppler o...

In this paper we transmit different complimentary codes using QPSK (Quadrature phase shift keying) modulation technique. The signal which is transmitted is scattered back from the target and send to the receiver for the demodulation. Using matlab a digital processing algorithm is designed for resolving range resolution and Doppler localization of a target using different complimentary codes lik...

Light carries a spin angular momentum associated with its polarization and an orbital angular momentum arising from its phase cross-section. Sound, being a longitudinal wave, carries no spin component but can carry an orbital component of angular momentum when endowed with an appropriate phase structure. Here, we use a circular array of loudspeakers driven at a common angular frequency ωs but w...

Sooyoung Kim Shin et al. 31 In high-speed multimedia satellite communication systems, it is essential to provide high-quality, economical services by using efficient transmission schemes which can overcome channel impairments appearing in the satellite link. This paper introduces techniques to compensate for rain attenuation and the Doppler shift in the satellite communication link. An adaptive...