Search results for "Direct-sequence spread spectrum"
showing 4 items of 4 documents
Enhanced islanding detection in smart interface protection systems of distributed generation
2021
The widespread presence of distributed generators (DGs) and storage systems (DSSs) in electricity grids has increased the risk of islanding occurrence. This phenomenon must be suitably managed by Distribution System Operators (DSO), in order to avoid adverse situations, in terms of grid-protection problems, equipment damage, safety hazards, power quality problems and so on. Currently anti-islanding protection functions are handled by interface protection systems (IPSs), which are built in accordance with relevant standards for DGs and DSSs connection to power systems. However, some problems may occur in case of operation within the so-called non detection zone (NDZ). This paper presents an …
Filtering out intersymbol interference in spread-spectrum communication systems
1979
In this letter the transfer characteristic of the optimum filter suitable for eliminating intersymbol interference in pseudo-noise spread-spectrum communication systems is determined. Such a characteristic is independent of the code sequence employed.
Signal-to-Noise Ratio in Bandpass Direct-Sequence Spread-Spectrum Modulation Systems
1982
The effects of a linear transmission channel on the performance of a correlator receiver for a direct-sequence spreadspectrum system are analyzed and a complete treatment of the influence of a periodic spreading code is carried out. The output data signal is obtained as a function of the channel characteristic and the code sequence employed; this allows maximizing the output signal level and evaluation of the influence of the synchronization error of the local code. The asymptotic value of the correlation loss has also been derived together with the intersymbol inteference power. The general expression of a figure of merit of the effectiveness of the system is also obtained in simple terms …
Signal detection for spread spectrum communication systems with gradient algorithm
2012
Retrieval process of original symbols of a spread spectrum based communication system is tried to be improved by Gradient Algorithm (GA) and Blind Source Separation (BSS) principles. Two simple schemes, based on two energy functions are presented. Time correlation properties of the channel are used as advantages in developing the filter coefficients for the receiver. Direct Sequence - Code Division Multiple Access (DS-CDMA) technique based system setup is used for algorithm testing purposes. This is identified as one of the most stable spread spectrum communication technique where most of the technologies developed for that are highly compatible with High Speed Packet Access (HSPA) transmis…