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This paper describes a number of techniques that use perfect reconstruction (PR) non-maximally decimated filter banks (NMDFBs) to implement variable bandwidth filters. These processes entail three tightly coupled tasks. The first task uses an M-path analysis filter bank to partition the full bandwidth input time series into a set of M reduced bandwidth, reduced sample rate, intermediate time series...
Frequency hopping (FH) is a spread spectrum transmission technique that achieves frequency diversity gain over frequency selective fading channels and also has a low probability of interception. This technique has been widely used in military applications, for its recognized anti-jamming performance, and in some wireless standards such as GSM and Bluetooth, for its interference resistance. Modern...
We present a new class of highly effective and low complexity digital filters for processing very wideband signals. Digital filtering for wideband signals is often limited by the number of arithmetic operations that has to be performed per input sampling interval. We will show the new architecture permits filtering to be performed on partitioned spectral segments of the input signal at significantly...
We propose a joint matched filtering (MF) and carrier recovery architecture based on perfect reconstruction (PR) non-maximally decimated filter bank (NMDFB). The NMDFB based processing not only provides low speed processing feature but also effectively deals with the cascade and parallel filtering problems that most conventional receivers adopt. We will show the NMDFB implementation of conventional...
Software defined radios require selectable bandwidth digital filters to process the many different bandwidth signals pulled from or inserted into the ether. Implementation considerations favor fixed length digital filters with fixed coefficients that can be implemented with hardwired multipliers. This paper describes two filter architectures that use M-path polyphase partitions to implement variable...
In this paper we present an extremely efficient FFT based spectrum analyzer that performs constant-Q spectral analysis. Each stage of the proposed structure is formed of a half-band filter and a 2-to-1 down sampler. It shifts successive lower octaves to the same spectral interval; consequently, the same octave processor can be applied in all the stages. Fourier transforms are normally used for performing...
Power consumption is one of the most critical issues in the portable software defined radio devices. A software radio receiver has to be able to select and, eventually, down convert a single narrowband channel from a collection of channels that in many practical cases are equally spaced and have equal bandwidth, while providing the minimum power consumption. In this paper we present an efficient solution...
In this paper we present an extremely efficient constant-Q spectrum analyzer. By using half-band filtering and 2-to-1 down-sampling, the traditional analyzer successively shifts lower octaves to the same spectral interval so that the same post-processing can be applied to all of them. To decrease the total workload of such a structure a 4-path polyphase filter could be used to perform a 4-to-1 down-sampling...
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