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—In this paper, we study the joint allocation of three types of resources, namely, power, subcarriers and relay nodes, in multi-relay assisted dual-hop cooperative OFDM systems. All the relays adopt the amplify-and-forward protocol and assist the transmission from the source to destination simultaneously but on orthogonal subcarriers. The objective is to(More)
For an improper complex signal <b>x</b>, its complementary covariance Exx<sup>T</sup> is not zero and thus it carries useful statistical information about <b>x</b>. Widely linear processing exploits Hermitian and complementary covariance to improve performance. In this paper, we extend the existing theory of widely linear complex Kalman filters (WLCKF) and(More)
—We present a general method for constructing radar transmit pulse trains and receive filters for which the radar point-spread function in delay and Doppler, given by the cross-ambiguity function of the transmit pulse train and the pulse train used in the receive filter, is essentially free of range sidelobes inside a Doppler interval around the(More)
Joint power allocation, relay selection, and sub-carrier assignment are critical and challenging for achieving full benefits of OFDM based cooperative relay networks. In this paper, we study such a problem in a dual-hop multi-relay OFDM system with an objective of maximizing the spectral efficiency under a total power constraint. The system consists of a(More)
—For a zero mean, proper, complex random vector x, the Hermitian covariance Exx H is a complete second-order characterization. However, if the vector x is improper, it is correlated with its complex conjugate, meaning Exx T = 0. This improper or complementary covariance must be accounted for in a complete second-order characterization. The improper(More)
In this paper, we consider a MIMO radar consisting of multiple collocated transmit/receive elements, where each transmit/receive pair operates at a different subcarrier frequency. Each transmit element is assumed to be waveform agile, meaning that it can select its waveform across time from a waveform library on a pulse by pulse basis. We consider a(More)
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