| 1. |
- Panahi, Ashkan, 1986, et al.
(författare)
-
Wideband waveform design for robust target detection
- 2015
-
Ingår i: ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings. - 1520-6149. - 9781467369978 ; 2015-August, s. 3926-3930
-
Konferensbidrag (refereegranskat)abstract
- © 2015 IEEE. Future radar systems are expected to use waveforms of a high bandwidth, with an advantage of an improved range resolution. Herein, a technique to design robust wideband waveforms is developed. The context is detection of a single object with partially unknown parameters. The technique achieves an optimal detection speed for a desired resolution, maintaining a high detection performance. Many radar systems also require fast adaptation to a variable environment. Hence, the technique is devoted to rapidly design waveforms. In terms of probabilities of detection and false alarm, numerical evaluation shows the efficiency of the method when compared with a chirp signal and a Gaussian pulse.
|
|
| 2. |
- Ström, Marie, 1984
(författare)
-
Waveform and Receiver Filter Selection for Wideband Radar Applications
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis concerns the design of transmitter-receiver chains for widebandradar systems. The transmitter side employs one, or several, highly flexiblesignal generators, which are able to generate signals with a large bandwidth.At the receiver side, when we are are able to select receiver filters, we havethe freedom to optimize also the receiver filters.Herein, the transmit waveforms and receiver filters are designed to fulfiluser-defined criteria. In general, a high probability of target detection, whilemaintaining a low false alarm rate, is desired. For a scenario in which interferenceis present, this means to achieve a high Signal-to-Interference-and-NoiseRatio.When advanced transmitter-receiver technology is implemented, the possibilityto adapt the system through a feedback loop arises. Informationabout the the radar operating environment is provided by signal processingtechniques. We propose a Kalman filter to follow a time-evolving cluttermap,based on the complex received signal samples. The estimates of thecomplex clutter reflections are utilized to determine parameters of the clutterdistribution.The system should, in addition, experience a robust target detection property.This is important when targets are not confined on a user-specified gridof time-delays and time-scalings. We derive an algorithm where the mainlobewidth of the correlation function is adapted according to a desired resolution.The thesis also deals with hardware restrictions. A study on how to synthesizetime domain signals from achieved power spectra is performed. Wesynthesize signals with given spectral properties that experience a low peakto-average-power ratio. A signal with constant envelope is also achievable byallowing the power spectrum to deviate somewhat from its desired shape.
|
|
| 3. |
- Ström, Marie, 1984, et al.
(författare)
-
Wideband Waveform and Receiver Filter Bank Design for Clutter Suppression
- 2015
-
Ingår i: IEEE Journal on Selected Topics in Signal Processing. - : Institute of Electrical and Electronics Engineers (IEEE). - 1941-0484 .- 1932-4553. ; 9:8, s. 1366-1376
-
Tidskriftsartikel (refereegranskat)abstract
- Modern wideband radar systems with long integration time, equipped with arbitrarily waveform generators, raise a demand for advanced signaling transmission schemes. In this paper, we propose two algorithms to select transmit waveforms and receiver filters. The techniques are based on a clutter suppression criterion. For the first algorithm, we employ an optimized filter bank, and for the second algorithm, we use a matched filter bank. Clutter suppression is achieved by minimizing the correlation between receiver filters and interfering clutter echoes. The algorithm, for the optimized filter bank, is extended to adapt the transmission scheme and receiver filters to a time-evolving scenario. Adaptation parameters are based on estimates of a clutter map and detected target characteristics. To estimate the clutter map we propose a Kalman filter, whereas target parameters are calculated using a least-squares fit to data. The efficiency of the algorithms and the adaptation scheme are visualized through a numerical simulation.
|
|
