Spread spectrum demodulator using block signal processing

Abstract

This paper shows a DirectSequence Spread-Spectrum (SS-DS) demodulator using block signal processing. Our proposed SS-DS demodulator uses the block signal processing, unlike the conventional SS-DS demodulators using real time signal processing. Received signal demodulated quasi-coherently is once stored in memory, and after extracting matchedpulse timing and estimating carrier offset, the signal is demodulated. Incoming data, therefore, are all demodulated without being lost by the initial-acquisition time, and our proposed SS-DS demodulator can provide the high data transmission efficiency.

Misclassification Probability Bounds for Multivariate Gaussian Classes

“…The error probability P(E ) is commonly estimated by Monte Carlo simulation of the classification problem (see, e.g., [4,5]). The simulation result is binomially distributed with mean P( E ) and standard deviation MC related to the number of trials N by [8] …”

“…Monte Carlo methods are frequently used as an alternative to integration (see, e.g., [4,5]). In Monte Carlo simulations, the number of trials must be chosen to ensure that the standard deviation on the estimate of error probability is small in comparison with the estimate.…”

Spread-spectrum block demodulator with high capacity crosscorrelation canceller

“…And the signal is fed to matched-filter. The matched-pulse (autocorrelation peak) timing can be detected almost accurately because of the periodicity and sharp autocorrelation function of PNcode [2] [8]. And the carrieroffset estimation can be also achieved almost accurately by means of FFT and…”

“…[6][7] [8]. In the demodulator, the received packet signal is demodulated quasi-coherently and transformed to a complex signal, then is digitized and stored in the buffer memory under a packet-by-packet basis.…”

“…The detailed block diagram of SSDS block demodulator is shown in Fig.2. It is composed of quasi-coherent demodulator, buffer memory, timing extractor and estimator [2][6] [8]. Received signal demodulated quasi-coherently is stored once in the memory, and then is fed to a variable digital-matched filter.…”