We apply the theory of Weyl-Heisenberg frames (WHFs) to oversampled FIR and IIR DFT filter banks (FBs). We show that the polyphase matrices provide a matrix representation of the frame operator, and we find conditions on a DFT FB to provide a WHF expansion. We also show that paraunitary and biorthogonal DFT FBs correspond to tight and exact WHFs, respectively, and that the frame bounds can be o...

In contemporary wireless communication systems, complementary sequences play fairly important roles. Based on polyphase perfect sequences (PPSs), this paper presents a construction method, whose basic idea is to sample a given PPS with equal space, for yielding a family of periodic polyphase complementary sequence sets (PPCSSs). The advantages of this method include the family size of resultant...

Polyphase IIR structures are known to be very attractive for very high performance filters that can be designed using very few coefficients. This combined with their reduced sensitivity to coefficient quantization in comparison to standard FIR and IIR structures makes them very applicable to very fast filtering especially when implemented in fixed point arithmetic. In this paper we suggest repl...

In order to solve the recognition of polyphase code radar signal, this paper gives two methods based on Frank code, i.e. the high-order spectrum recognition method and the fractional Fourier transform (FRFT) method, by analyzing the micro characteristics of polyphase code signals in time and frequency domain respectively. And a recognition algorithm based on Wigner-Hough transform (WHT) is deve...

We investigate and compare the computational loads of different implementations of a system for asynchronous sample rate reduction: The cascade of a preceding synchronous polyphase L-Interpolator, an asynchronous sample rate converter applying five different Farrow structures being based on Lagrange interpolation and a successive synchronous polyphase M-decimator. For a limited range of require...

CλaSH, a functional hardware description language based on Haskell, has several abstraction mechanisms that allow a hardware designer to describe architectures in a short and concise way. In this paper we evaluate CλaSH on a complex DSP application, a Polyphase Filter Bank as it is used in the ASTRON APERTIF project. The Polyphase Filter Bank is implemented in two steps: first in Haskell as bei...

Vulnerability in the interception of radar transmission by anti-radiation missiles or the like, can be avoided by using Low Probability of Intercept (LPI) techniques like Barker codes, Frank codes, polyphase codes, Costas code, etc. In this project, we simulate different kinds of complex waveforms that are obtained by superimposing LPI signal onto the radar signal. Analysis of the power spectra...

A novel first-order active-RC polyphase filter section, using current differencing buffered amplifiers (CDBAs), is presented. The section uses 6 resistors, 2 capacitors, and 2 CDBAs. The transfer function of the proposed section has a single pole and optionally a single zero. Increasing the number of cascading sections, any higher order polyphase filter can be realized. This paper also introduc...

This paper provides a tutorial overview of multichannel wireless digital receivers and the relationships between channel bandwidth, channel separation, and channel sample rate. The overview makes liberal use of figures to support the underlying mathematics. A multichannel digital receiver simultaneously down-convert a set of frequency-division-multiplexed (FDM) channels residing in a single sam...