In this paper, a novel algorithm that resembles amplitude demodulation in the frequency domain is introduced, and its application to automatic speech recognition (ASR) is studied. Speech production can be regarded as a result of amplitude modulation (AM) with the source (excitation) spectrum being the carrier and the vocal tract transfer function (VTTF) being the modulating signal. From this po...

The Karhunen-Loeve Transform (KLT) is applied to accurate detection of optical fiber sensors in the spectral domain. By processing an optical spectrum, although coarsely sampled, through the KLT, and subsequently processing the obtained eigenvalues, it is possible to decode a plurality of optical sensor results. The KLT returns higher accuracy than other demodulation techniques, despite coarse ...

This paper proposes iterative demodulation/decoding for parallel combinatorial spread spectrum (PC/SS) systems. A PC/SS system conveys information data by a combination of pre-assigned orthogonal spreading sequences with polarity. In this paper, convolutional coding with a uniform random interleaver is implemented in channel coding, just like as a serial concatenated coding. A ‘soft-in/soft-out...

The discrete multitone @MT) modulation/demodulation scheme is the standard transmission technique in the application of asymmetric digital subscriber lines (ADSL). Although the DMT can achieve higher data rate compared with other modulation/ demodulation schemes, its computational complexity is too high for cost-efficient implementations. For example, it requires 512. point IFFUFIT as the modul...

This paper addresses the fixed-point DSP implementation of FM demodulation and decoding for the digital radio application. The demodulation module involves division and arctan for which there is no dedicated hardware on a fixed-point DSP. Division is normally achieved either by using the Newton-Raphson method or by using conditional subtraction instruction. It is normally more efficient to use ...

The Aircraft Communication Addressing and Reporting System (ACARS) is playing an increasingly important role to guarantee the safety and the efficiency of aircraft, so more effective method of receiving is necessary. The modulation of the ACARS system is MSK, the aim of this paper is to find a better demodulation method for the signal of ACARS. The characteristic of mapping relationship between...

AbsfrucfOrthogonal Frequency Division Multiplexing (OFDM) [l] is often proposed for high data rate transmission over frequency-selective channels in order to simplify equalisation. In this paper 4and &PSK and DPSK with coherent and non-coherent demodulation are considered for performance comparison. A channel estimation and equalisation is necessary for coherent demodulation whereas this effort...

J”his paper proposes three so-called pscudocohcrcnt demodulation schemes for usc in land mobile satellite channels, ‘J’he schcmcs arc derived based on maximum-likelihood (Ml.) estimation and dckction of an N-symbol observation of ttm received signal, Simulation results for all three demodulators arc presented to allow comparison with the performance of differential PSK (DPSK), and ideal coheren...

In this paper, we propose a novel on-line blind demodulation algorithm for Quadrature Amplitude Modulation (QAM). The proposed approach can demodulate QAM signal without constellation knowledge, and reach the theoretical optimal performance under the constraint of sequential detection. Numerical simulations are provided to validate the analytical results. Results show that when iterations are l...