Cognitive radar can adjust its transmission signals in real time based on the battlefield situation, effectively improving its detection performance in complex electromagnetic environments. In response to the requirem...
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ISBN:
(纸本)9798400707674
Cognitive radar can adjust its transmission signals in real time based on the battlefield situation, effectively improving its detection performance in complex electromagnetic environments. In response to the requirement of high sidelobe suppression within the target tracking stage's range gate, this paper proposes a waveform optimization method based on specific distance sidelobe suppression, utilizing the uniform sidelobe properties of the polyphase-coded signals. This method uses the polyphase coding as the initial sequence and minimizes the specific distance matrix while maintaining sequence constant modulus as the optimization conditions, achieving low autocorrelation sidelobes within the specific distance range. Simulation results demonstrate that the waveforms obtained through this method can effectively reduce interference from known multipath and clutter within a given distance gate, achieving sidelobe reduction of up to 60 dB within the specific distance range, thereby significantly enhancing the capability to detect small targets.
In ambient rescatter communications, devices convey information by modulating and rescattering the radio frequency signals impinging on their antennas. In this correspondence, we consider a system consisting of a lega...
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In ambient rescatter communications, devices convey information by modulating and rescattering the radio frequency signals impinging on their antennas. In this correspondence, we consider a system consisting of a legacy modulated continuous carrier multiple-input-multiple-output link and a multiantenna modulated rescatter (MRS) node, where the MRS node modulates and rescatters the signal generated by the legacy transmitter. The receiver seeks to decode both the original message and the information added by the MRS. We show that the achievable sum rate of this system exceeds that which the legacy system could achieve alone. We further consider the impact of channel estimation errors under the least squares channel estimation and study the achievable rate of the legacy and MRS systems, where a linear minimum mean square error receiver with successive interference cancellation is utilized for joint decoding.
Weighting method by window function is used in order to improve the properties of the code in polyphase pulse compression Radars. This paper investigates and compares the effect of weighting methods in frequency domai...
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ISBN:
(纸本)9781467311496
Weighting method by window function is used in order to improve the properties of the code in polyphase pulse compression Radars. This paper investigates and compares the effect of weighting methods in frequency domain and in amplitude, with Hamming window, on three common types of codes namely;Frank, P3 and P4 polyphase codes. It is shown that the weighting in the frequency domain improves the properties of the Frank and P3 codes, but has negative impacts P4 code. Amplitude weighting on the other hand, improve the properties of both P3 and P4 codes, but increases the sidelobes near the signal peak in the Frank code.
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