The article reviews and summarizes the results of a Norden study to evaluate real-time JPEG and wavelet compression of the RS-170 images taken from the display of the APG-76 high resolution SAR multimode radar system and transmitted to the ground. The significant advantages of this compression are twofold: the ability to retain large quantities of flight test images at better compression rates than that provided by the lossless GIF format; and the ability to transmit the images in near-real time from the ground station to a home base over standard telephone lines or even over a cellular phone. We have investigated several techniques, considered in the literature to be at or near the state of the art, for lossy compression of APG-76 radar images captured on the ground. We have achieved up to 15:1 in JPEG compression rates without significant picture degradation, if the images are first de-noised. If the pictures are not de-noised, then an 8:1 compression rate can be achieved with little degradation, but at 15:1, JPEG does degrade the images. Although in 1995 we could find no wavelet technique that bettered JPEG, we recently acquired a wavelet implementation that, at 15:1 compression, measured nearly 30 dB in peak signal to noise ratio (PSNR), and was 1.6 dB better than JPEG. This represents a long step towards the 3 dB PSNR improvement required to achieve 2:1 compression improvement over JPEG.
本文回顾和总结了Norden研究的结果，以评估从APG-76高分辨率SAR多模雷达系统显示并传输到地面的RS-170图像的实时JPEG和小波压缩。这种压缩的显著优势是双重的:能够以比无损GIF格式提供的更好的压缩率保留大量飞行测试图像;以及通过标准电话线甚至蜂窝电话将图像近乎实时地从地面站传输到家庭基地的能力。我们研究了几种技术，在文献中被认为是处于或接近最先进的状态，用于在地面上捕获的APG-76雷达图像的有损压缩。如果图像首先去噪，我们已经实现了高达15:1的JPEG压缩率，而没有明显的图像退化。如果图片没有去噪，那么可以实现8:1的压缩率而几乎没有降级，但是在15:1时，JPEG确实会降低图像的降级。虽然在1995年我们没有发现比JPEG更好的小波技术，但我们最近获得了一种小波实现，在15:1压缩下，测量到峰值信噪比(PSNR)接近30 dB，比JPEG好1.6 dB。这代表了向实现比JPEG 2:1的压缩改进所需的3 dB PSNR改进迈出的一大步。
{"title":"Techniques for real-time compression of RS-170 high resolution radar images","authors":"A. D. Aronoff","doi":"10.1109/TCC.1996.561123","DOIUrl":"https://doi.org/10.1109/TCC.1996.561123","url":null,"abstract":"The article reviews and summarizes the results of a Norden study to evaluate real-time JPEG and wavelet compression of the RS-170 images taken from the display of the APG-76 high resolution SAR multimode radar system and transmitted to the ground. The significant advantages of this compression are twofold: the ability to retain large quantities of flight test images at better compression rates than that provided by the lossless GIF format; and the ability to transmit the images in near-real time from the ground station to a home base over standard telephone lines or even over a cellular phone. We have investigated several techniques, considered in the literature to be at or near the state of the art, for lossy compression of APG-76 radar images captured on the ground. We have achieved up to 15:1 in JPEG compression rates without significant picture degradation, if the images are first de-noised. If the pictures are not de-noised, then an 8:1 compression rate can be achieved with little degradation, but at 15:1, JPEG does degrade the images. Although in 1995 we could find no wavelet technique that bettered JPEG, we recently acquired a wavelet implementation that, at 15:1 compression, measured nearly 30 dB in peak signal to noise ratio (PSNR), and was 1.6 dB better than JPEG. This represents a long step towards the 3 dB PSNR improvement required to achieve 2:1 compression improvement over JPEG.","PeriodicalId":398935,"journal":{"name":"Proceedings of the 1996 Tactical Communications Conference. Ensuring Joint Force Superiority in the Information Age","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124094370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, a wavelet-based multiple access system, STCDMA (scale-time-code-division multiple access), which is based on the scale, time, and code orthogonality has been described and its performance has been analyzed for synchronous transmission in an AWGN channel. In a synchronous AWGN channel, Hadamard codebased PN sequences keep their orthogonality and hence STCDMA achieves optimum single-user BPSK performance by using a conventional single-user detector for each user. It also supports a larger number of users than conventional DS-CDMA (six or seven times more than DS-CDMA) if the first (coarsest) scale is thought to be traditional DS-CDMA. When we use other wavelets than the Haar wavelet, or the signature waveforms exhibit some correlation in other environments such as asynchronous AWGN channel and the multipath propagation medium, the system will have multiple access interference.
{"title":"Scale-time-code-division multiple access (STCDMA)","authors":"O. Kucur, G. Atkin","doi":"10.1109/TCC.1996.561117","DOIUrl":"https://doi.org/10.1109/TCC.1996.561117","url":null,"abstract":"In this work, a wavelet-based multiple access system, STCDMA (scale-time-code-division multiple access), which is based on the scale, time, and code orthogonality has been described and its performance has been analyzed for synchronous transmission in an AWGN channel. In a synchronous AWGN channel, Hadamard codebased PN sequences keep their orthogonality and hence STCDMA achieves optimum single-user BPSK performance by using a conventional single-user detector for each user. It also supports a larger number of users than conventional DS-CDMA (six or seven times more than DS-CDMA) if the first (coarsest) scale is thought to be traditional DS-CDMA. When we use other wavelets than the Haar wavelet, or the signature waveforms exhibit some correlation in other environments such as asynchronous AWGN channel and the multipath propagation medium, the system will have multiple access interference.","PeriodicalId":398935,"journal":{"name":"Proceedings of the 1996 Tactical Communications Conference. Ensuring Joint Force Superiority in the Information Age","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126821681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A new method is described for routing multimedia traffic in a frequency-hop (FH) store-and-forward packet radio network. The new routing protocol is an extension of least-resistance routing (LRR), which bases route selection on the resistances for the routes from the source to the destination. The link resistance for LRR is a measure of the interference environment and other conditions that affect the probability that a FH radio can receive and forward a packet. For multimedia least-resistance routing (MMLRR), the link resistance for a given type of packet also accounts for the service requirements of that packet. MMLRR is illustrated for two types of traffic, each type having its own constraints on the number of errors and the delay. A typical application is the routing of voice and data packets in a multiple-hop network. In such an application, the voice packets cannot tolerate much delay, but they are allowed to contain a small number of errors. The data packets must be delivered error-free, even if a moderate delay is required to do so. The performance of MMLRR is measured by the throughput, end-to-end success probability, and delay which are obtained by computer simulation of a multiple-hop network of FH radios.
{"title":"Measuring the link qualities in a frequency-hop packet radio network for use in the routing of multimedia packets","authors":"M. Pursley, H. Russell, P. E. Staples","doi":"10.1109/TCC.1996.561094","DOIUrl":"https://doi.org/10.1109/TCC.1996.561094","url":null,"abstract":"A new method is described for routing multimedia traffic in a frequency-hop (FH) store-and-forward packet radio network. The new routing protocol is an extension of least-resistance routing (LRR), which bases route selection on the resistances for the routes from the source to the destination. The link resistance for LRR is a measure of the interference environment and other conditions that affect the probability that a FH radio can receive and forward a packet. For multimedia least-resistance routing (MMLRR), the link resistance for a given type of packet also accounts for the service requirements of that packet. MMLRR is illustrated for two types of traffic, each type having its own constraints on the number of errors and the delay. A typical application is the routing of voice and data packets in a multiple-hop network. In such an application, the voice packets cannot tolerate much delay, but they are allowed to contain a small number of errors. The data packets must be delivered error-free, even if a moderate delay is required to do so. The performance of MMLRR is measured by the throughput, end-to-end success probability, and delay which are obtained by computer simulation of a multiple-hop network of FH radios.","PeriodicalId":398935,"journal":{"name":"Proceedings of the 1996 Tactical Communications Conference. Ensuring Joint Force Superiority in the Information Age","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123875835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Spread spectrum packet radio networks are being proposed to support tactical communications in highly mobile battlefield environments. Direct sequence packet radio waveforms offer certain benefits that provide antijamming (A/J) and LPI protection while reducing the effects of multipath and providing rapid acquisition. However, near/far interference restricts the performance of a direct sequence type waveforms in a tactical network where the relative power of each transmitting node cannot be centrally controlled. This paper reviews the implementation and analysis of adaptive power control for a spread spectrum waveform within a hierarchical packet radio network. The adaptive power control algorithm operates in conjunction with a receiver directed/reservation-based channel access protocol that uses a sequence of short synchronization and acknowledgment bursts to reserve the channel and adapt the transmit power for the exchange of direct sequence modulated data packets. The waveform, channel access protocol and power control algorithm operate within a hierarchical packet radio network that supports 400 or more radio nodes within a Brigade size area of 20/spl times/30 km. The network of radio nodes is divided into clusters that communicate locally. Clusterheads within each cluster form, a virtual backbone for intercluster packet exchange. This paper presents an overview of the waveform, protocols and power control algorithm that support the packet exchange process. Modeling results are presented to show the relative throughput, delay and reliability performance of the network versus various adaptive power control parameters.
{"title":"Evaluation of adaptive power control algorithms for a hierarchical packet radio network","authors":"T. Dempsey, C. Langford, R. Martin, J. McChesney","doi":"10.1109/TCC.1996.561102","DOIUrl":"https://doi.org/10.1109/TCC.1996.561102","url":null,"abstract":"Spread spectrum packet radio networks are being proposed to support tactical communications in highly mobile battlefield environments. Direct sequence packet radio waveforms offer certain benefits that provide antijamming (A/J) and LPI protection while reducing the effects of multipath and providing rapid acquisition. However, near/far interference restricts the performance of a direct sequence type waveforms in a tactical network where the relative power of each transmitting node cannot be centrally controlled. This paper reviews the implementation and analysis of adaptive power control for a spread spectrum waveform within a hierarchical packet radio network. The adaptive power control algorithm operates in conjunction with a receiver directed/reservation-based channel access protocol that uses a sequence of short synchronization and acknowledgment bursts to reserve the channel and adapt the transmit power for the exchange of direct sequence modulated data packets. The waveform, channel access protocol and power control algorithm operate within a hierarchical packet radio network that supports 400 or more radio nodes within a Brigade size area of 20/spl times/30 km. The network of radio nodes is divided into clusters that communicate locally. Clusterheads within each cluster form, a virtual backbone for intercluster packet exchange. This paper presents an overview of the waveform, protocols and power control algorithm that support the packet exchange process. Modeling results are presented to show the relative throughput, delay and reliability performance of the network versus various adaptive power control parameters.","PeriodicalId":398935,"journal":{"name":"Proceedings of the 1996 Tactical Communications Conference. Ensuring Joint Force Superiority in the Information Age","volume":"423 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126713308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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