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The comparison of signal spectrum diagram in the condition of BPSK jamming. a The classic DSSS technology. b The proposed method
Source publication
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In cognitive radio (CR), cognitive users can sense the wholes and white spectrum and generate spectrum notch in the spectrum bands occupied by primary users (PUs) or interference. Thus, the key technology in CR is to control the spectrum shape of the transmitted signal to avoid PUs and interference. In this paper, a new method of shaping the transm...
Citations
... And [8][9] propose the user uses different chip symbol waveforms, and the bit error rate performance is different under multiple access interference. [10] shows that by designing the chip symbol waveform, it can make the spread spectrum user transmit a certain spectrum zero filling characteristic. If a suitable chip symbol waveform is designed or selected, it is possible to improve the antimultipath, anti-multiple access and spectrum zero filling characteristics of the composite CDMA users. ...
The versatility of simple electronic nodes and debugging of communication protocols in unlicensed frequency bands constitute the main reasons for the adoption of industrial wireless sensor networks (IWSNs). However, the industrial environments, in which IWSNs function, are characterized by a harsh impact of physical and electromagnetic factors that destabilize the operation of equipment and worsen the noise immunity of channels. To consider the effect of these two groups of factors on communication quality, we develop a novel model of an IWSN channel as the dependence of bit error probability (BEP) on signal distortions and interference impact. We found that direct sequence spread spectrum (DSSS) codes of a signal have different effects on the compensation of nonlinear signal distortions and external interference. Further, we propose an algorithm for the distribution of DSSS codes among real transmitters by BEP values in channels with known additive and multiplicative interference. Here, the distribution of codes is based on the minimax criterion. Finally, for cases when a signal is characterized by a-priori uncertainties of fading, we suggest an alternative algorithm for selecting a DSSS code based on Pareto bicriteria optimization.
