In the digital synthesis of wideband periodic signals using an Arbitrary Waveform Gen-erator(AWG),the frequency resolution and spectral complexity of the synthesized signals are com-monly limited by the memory capacit...In the digital synthesis of wideband periodic signals using an Arbitrary Waveform Gen-erator(AWG),the frequency resolution and spectral complexity of the synthesized signals are com-monly limited by the memory capacity and clock frequency of the AWG.This paper proposes a novel sequential addressing scheme and then presents several sequences to improve the frequency resolution of the synthesized periodic signals without changing their spectral envelopes and basic time-domain characteristics under the condition of a fixed memory capacity and a fixed clock fre-quency.The main idea of the scheme is using the address generator in an AWG to program and produce addresses to read fixed waveform data in variable order,and thus to generate waveforms of various periods and profiles.The scheme is applied in simulating signal scenarios for military com-munication countermeasure experiments,and achieves high performance.展开更多
In this paper we give a sufficient and necessary condition under which a continuous measure (whose values belong to, the extended half-line (0,+∞) defined on a class of sets closed under the formation of intersection...In this paper we give a sufficient and necessary condition under which a continuous measure (whose values belong to, the extended half-line (0,+∞) defined on a class of sets closed under the formation of intersection can be extended to a smallest monotone class containing this class, and we also give a condition under which there exists a unique extension. In addition, we give a method by means of which a continuous measure on a monotone class can be extended again.展开更多
基金the National Grand Fundamental Research 973 Program of China (No.2004CB318109)the National High-Technology Research and Development Plan of China (No.2006AA01Z452)
文摘In the digital synthesis of wideband periodic signals using an Arbitrary Waveform Gen-erator(AWG),the frequency resolution and spectral complexity of the synthesized signals are com-monly limited by the memory capacity and clock frequency of the AWG.This paper proposes a novel sequential addressing scheme and then presents several sequences to improve the frequency resolution of the synthesized periodic signals without changing their spectral envelopes and basic time-domain characteristics under the condition of a fixed memory capacity and a fixed clock fre-quency.The main idea of the scheme is using the address generator in an AWG to program and produce addresses to read fixed waveform data in variable order,and thus to generate waveforms of various periods and profiles.The scheme is applied in simulating signal scenarios for military com-munication countermeasure experiments,and achieves high performance.
文摘In this paper we give a sufficient and necessary condition under which a continuous measure (whose values belong to, the extended half-line (0,+∞) defined on a class of sets closed under the formation of intersection can be extended to a smallest monotone class containing this class, and we also give a condition under which there exists a unique extension. In addition, we give a method by means of which a continuous measure on a monotone class can be extended again.
