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The following topics are dealt with: waveform diversity; radar; sonar, navigation; radio channels; target tracking; MIMO communication; UWB communication
Waveform diversity in distributed radio frequency (RF) sensor systems offers the potential for breakthrough performance enhancements in the detection and identification of natural and manmade objects. This paper discusses advances in relevant technology and emerging applications to radar
Echo locating mammals such as bats, whales and dolphins have been using waveform diversity for over 50 million years. They vary the PRF, the power and the frequency content of the transmitted waveforms. This has enabled them to evolve highly sophisticated navigation techniques and the ability to forage for food. Moreover, recent developments in technology means that it is now possible to replicate...
Passive coherent location (PCL) radar systems that use single FM radio channel signal as illuminator of opportunity have limited range resolution due to low modulation bandwidth and high dependence on the content that is being broadcasted from the FM station. An improvement in range resolution is obtained by using multiple adjacent FM channels, emitted from co-sited transmitters, which is often the...
This paper serves to provide a thorough introduction to chaotic signal generation and chaotic radar waveform modulation, emphasizing the diversity and ease of variation of such waveforms. Results of their adaptation to a specific waveform performance objective are presented as is their potential use as target matched waveforms
SAR images of moving targets are blurred, defocused and displaced from their true location making them difficult to detect from their direct energy returns. This paper presents an alternate technique for detecting such targets by exploiting the phenomenon that the shadow projected by the target produce a null in the SAR imagery. The target shadow is presented at its true location and tracks the target...
In this article, phase conjugation in radar is studied. A method developed by ONERA (Van Atta, 1955) is used and then the performances of the process are evaluated. Comparisons between phase conjugation and classical radar processes are established
A brief historical perspective of the evolution of waveform designs employed in consecutive generations of wireless communications systems is provided, highlighting the range of often conflicting demands on the various waveform characteristics. As the culmination of recent advances in the field the underlying benefits of various multiple input multiple output (MIMO) schemes are highlighted and exemplified...
This paper considers the evolution to multiple input, multiple output (MIMO) communications, which has its origins in both spatial processing and temporal processing. In the context of this paper, the term 'spatial processing' is taken to include classical/adaptive beamforming and sub-space analysis, whereas the term 'temporal processing' is taken to include the subjects of error control coding, interleaving...
In this paper, the authors present the design and modelling aspects of UWB turbo codes and UWB SCCCs, along with their performance analysis in comparison with the FEC method recommended by the UWB specifications. The authors consider both the direct spread and multi-carrier versions of UWB in the presence of additive white Gaussian noise (AWGN) channel as well as IEEE 802.15.3 channel models. The...
Interleaved coding-modulation (ICM) is a recently proposed method for ultra-wideband impulse radio (UWB-IR) systems. ICM exploits the concept of chip interleaving, allowing to alleviate the problem of inter-symbol and inter-pulse interference commonly present in high data rate UWB-IR systems. In this paper, the authors extend previous work on ICM to scarcely populated multi-user scenarios. The authors...
The application of multi-rate processing to target location is considered in this paper. This technique is shown to refocus the corresponding ambiguity function, giving rise to the possibility of enabling diversity to be used for the benefits of enhancing both accuracy and resolution of a target. Attention is paid to the geolocation of radio frequency (RF) emitters; however, this technique can be...
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