Pub Date : 2001-10-28DOI: 10.1109/MILCOM.2001.986053
Wen-Jye Huang, J. Doherty
Space division multiple access (SDMA) uses the advantage of the smart antenna technology to form a directional antenna pattern in a cellular. By exploiting the directional antenna pattern for users, SDMA can achieve spatial orthogonality among users and channel reuse within a cell. Several studies (Fuhl 1997; Buracchini et al. 1996) have shown the performance improvement of SDMA in a mobile communication environment. This paper extends the two-folding SDMA blocking probability derivation from Galvan-Tejada and Gardiner (1999) and approximately two-folding SDMA approaches from Huang and Doherty (2001). An approximate model is proposed for three-folding SDMA and the corresponding blocking probability is derived. Analytical and simulation results show that three-fold SDMA increases capacity over the traditional cellular system, which demonstrates the effectiveness of SDMA for resource management.
空分多址(SDMA)利用智能天线技术的优势，在蜂窝内形成定向天线方向图。通过利用用户的定向天线方向图，SDMA可以实现用户间的空间正交性和小区内的信道复用。几项研究(Fuhl 1997;Buracchini et al. 1996)已经证明了SDMA在移动通信环境下的性能改进。本文扩展了galvana - tejada和Gardiner(1999)的双折叠SDMA阻塞概率推导以及Huang和Doherty(2001)的近似双折叠SDMA方法。提出了三折叠SDMA的近似模型，并推导了相应的阻塞概率。分析和仿真结果表明，在传统蜂窝系统的基础上，三倍的SDMA增加了容量，证明了SDMA在资源管理方面的有效性。
{"title":"An evaluation of blocking probability for three-fold SDMA","authors":"Wen-Jye Huang, J. Doherty","doi":"10.1109/MILCOM.2001.986053","DOIUrl":"https://doi.org/10.1109/MILCOM.2001.986053","url":null,"abstract":"Space division multiple access (SDMA) uses the advantage of the smart antenna technology to form a directional antenna pattern in a cellular. By exploiting the directional antenna pattern for users, SDMA can achieve spatial orthogonality among users and channel reuse within a cell. Several studies (Fuhl 1997; Buracchini et al. 1996) have shown the performance improvement of SDMA in a mobile communication environment. This paper extends the two-folding SDMA blocking probability derivation from Galvan-Tejada and Gardiner (1999) and approximately two-folding SDMA approaches from Huang and Doherty (2001). An approximate model is proposed for three-folding SDMA and the corresponding blocking probability is derived. Analytical and simulation results show that three-fold SDMA increases capacity over the traditional cellular system, which demonstrates the effectiveness of SDMA for resource management.","PeriodicalId":136537,"journal":{"name":"2001 MILCOM Proceedings Communications for Network-Centric Operations: Creating the Information Force (Cat. No.01CH37277)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123868106","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}
Pub Date : 2001-10-28DOI: 10.1109/MILCOM.2001.986102
C. Hessel
This paper explains the relationships between MIL-STD-188-181b, MIL-STD-188-184, High Performance Waveform modulation and High Performance Waveform protocol. We discuss the important features of each of these items, their similarities and differences, and how these various pieces do and do not work together. The paper discusses these issues with regard to non-DAMA satellite communications since, at the time of this writing, 181b and 184 are not officially part of DAMA.
{"title":"High Performance Waveform, MIL-STD-188-181b and MIL-STD-188-184: their differences, similarities and applications","authors":"C. Hessel","doi":"10.1109/MILCOM.2001.986102","DOIUrl":"https://doi.org/10.1109/MILCOM.2001.986102","url":null,"abstract":"This paper explains the relationships between MIL-STD-188-181b, MIL-STD-188-184, High Performance Waveform modulation and High Performance Waveform protocol. We discuss the important features of each of these items, their similarities and differences, and how these various pieces do and do not work together. The paper discusses these issues with regard to non-DAMA satellite communications since, at the time of this writing, 181b and 184 are not officially part of DAMA.","PeriodicalId":136537,"journal":{"name":"2001 MILCOM Proceedings Communications for Network-Centric Operations: Creating the Information Force (Cat. No.01CH37277)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124203389","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}
Pub Date : 2001-10-28DOI: 10.1109/MILCOM.2001.986090
Ping Xiong, I. Psaromiligkos, S. Batalama
We investigate the relative output SINR performance of two linear multiuser detectors - the full decorrelator and the partial decorrelator. For each detector, we consider two implementations that are equivalent under perfectly known input statistics. The first implementation utilizes the signature matrix while the second implementation is based on the eigendecomposition of the ideal input covariance matrix. While the full decorrelator aims at decorrelating the complete multiple-access-interference, the partial decorrelator aims at decorrelating only a part of it by excluding one or more user-signatures or eigenvectors from the corresponding implementation method. We derive necessary and sufficient conditions on the signal energy and signature cross-correlation levels under which the partial decorrelator outperforms the full decorrelator in the output SINR sense. Numerical results demonstrate the validity of the above conditions and simulation studies illustrate the relative SINR and BER performance of the full and partial decorrelators under sample-average-estimated input statistics.
{"title":"On the relative output SINR of the full and partial decorrelators","authors":"Ping Xiong, I. Psaromiligkos, S. Batalama","doi":"10.1109/MILCOM.2001.986090","DOIUrl":"https://doi.org/10.1109/MILCOM.2001.986090","url":null,"abstract":"We investigate the relative output SINR performance of two linear multiuser detectors - the full decorrelator and the partial decorrelator. For each detector, we consider two implementations that are equivalent under perfectly known input statistics. The first implementation utilizes the signature matrix while the second implementation is based on the eigendecomposition of the ideal input covariance matrix. While the full decorrelator aims at decorrelating the complete multiple-access-interference, the partial decorrelator aims at decorrelating only a part of it by excluding one or more user-signatures or eigenvectors from the corresponding implementation method. We derive necessary and sufficient conditions on the signal energy and signature cross-correlation levels under which the partial decorrelator outperforms the full decorrelator in the output SINR sense. Numerical results demonstrate the validity of the above conditions and simulation studies illustrate the relative SINR and BER performance of the full and partial decorrelators under sample-average-estimated input statistics.","PeriodicalId":136537,"journal":{"name":"2001 MILCOM Proceedings Communications for Network-Centric Operations: Creating the Information Force (Cat. No.01CH37277)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125141140","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}
Pub Date : 2001-10-28DOI: 10.1109/MILCOM.2001.986084
D. Torrieri
When power control is used in a cellular network, the base station attempts to either directly or indirectly track the received power of the desired signal from a mobile. As the fading rate increases, the tracking ability of a direct-sequence code-division multiple-access system deteriorates, and the power-control accuracy declines. It is shown that a large performance degradation occurs when the instantaneous signal level cannot be accurately measured, even when the channel-code interleaving is perfect. An alternative that is assumed by many authors is to measure a long-term-average signal level that averages out the fast fading effects. However it is shown that this approach is less viable than attempting to track the instantaneous signal level even if the latter results in large errors.
{"title":"Power-control problems caused by fast fading in a direct-sequence multiple-access network","authors":"D. Torrieri","doi":"10.1109/MILCOM.2001.986084","DOIUrl":"https://doi.org/10.1109/MILCOM.2001.986084","url":null,"abstract":"When power control is used in a cellular network, the base station attempts to either directly or indirectly track the received power of the desired signal from a mobile. As the fading rate increases, the tracking ability of a direct-sequence code-division multiple-access system deteriorates, and the power-control accuracy declines. It is shown that a large performance degradation occurs when the instantaneous signal level cannot be accurately measured, even when the channel-code interleaving is perfect. An alternative that is assumed by many authors is to measure a long-term-average signal level that averages out the fast fading effects. However it is shown that this approach is less viable than attempting to track the instantaneous signal level even if the latter results in large errors.","PeriodicalId":136537,"journal":{"name":"2001 MILCOM Proceedings Communications for Network-Centric Operations: Creating the Information Force (Cat. No.01CH37277)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131312392","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}
Pub Date : 2001-10-28DOI: 10.1109/MILCOM.2001.985775
Chiho Lee, Kwang-Eog Lee, Young-Kyun Choi, Kiseon Kim
In this paper, we analyze the effect of chip waveform on the detection performance of an energy detector in a multi-user DS/SS system. Detection performance of the partial-band detection is investigated together with the full-band detection for a DS/SS signal. In order to evaluate the detection performance of the partial-band detection, bandwidth factor and energy factor are introduced. Numerical results show that the partial-band detection strategy always produces better detection performance than the full-band detection strategy with a proper selection of partial-band detection bandwidth. In addition, among the compared three chip waveforms, such as rectangular, half-sine and raised-cosine waveform, the raised-cosine waveform; produces much lower detection probability compared with other waveforms, as the number of concurrent users increases.
{"title":"Analysis on detection performance of an energy detector for several chip waveforms in a DS/SS communication","authors":"Chiho Lee, Kwang-Eog Lee, Young-Kyun Choi, Kiseon Kim","doi":"10.1109/MILCOM.2001.985775","DOIUrl":"https://doi.org/10.1109/MILCOM.2001.985775","url":null,"abstract":"In this paper, we analyze the effect of chip waveform on the detection performance of an energy detector in a multi-user DS/SS system. Detection performance of the partial-band detection is investigated together with the full-band detection for a DS/SS signal. In order to evaluate the detection performance of the partial-band detection, bandwidth factor and energy factor are introduced. Numerical results show that the partial-band detection strategy always produces better detection performance than the full-band detection strategy with a proper selection of partial-band detection bandwidth. In addition, among the compared three chip waveforms, such as rectangular, half-sine and raised-cosine waveform, the raised-cosine waveform; produces much lower detection probability compared with other waveforms, as the number of concurrent users increases.","PeriodicalId":136537,"journal":{"name":"2001 MILCOM Proceedings Communications for Network-Centric Operations: Creating the Information Force (Cat. No.01CH37277)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130087506","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}
Pub Date : 2001-10-28DOI: 10.1109/MILCOM.2001.986027
K. Tepe, J.B. Anderson
Turbo coding is investigated for uninterleaved and partially interleaved Rayleigh fading channels. It is compared to ordinary convolutional coding with the same rate and memory 2, 4 and 8 best d/sub free/ encoders. When turbo frames are very long, turbo coding with a channel interleaver gets better bit error rates (BER) than ordinary convolutional coding with a channel interleaver. When the frames are shorter, lower complexity convolutional coding is as good as turbo coding. It is shown by experiment that only after a certain critical frame size does turbo coding get better BER than convolutional coding and the length of this threshold is linearly dependent on the inverse of the fading bandwidth, 1/BT. The effect of the constituent encoders on the error performance is also tested. Memory 2, 4 and 6 constituent encoders are compared. For short to moderate turbo frame size, the memory 2 constituent encoder is as good as the memory 4 and better than the memory 6 encoder. For very long block-lengths, the memory 4 encoder is the best. The memory 6 encoder is always the worst.
{"title":"Turbo coding behavior in Rayleigh fading channels without perfect interleaving","authors":"K. Tepe, J.B. Anderson","doi":"10.1109/MILCOM.2001.986027","DOIUrl":"https://doi.org/10.1109/MILCOM.2001.986027","url":null,"abstract":"Turbo coding is investigated for uninterleaved and partially interleaved Rayleigh fading channels. It is compared to ordinary convolutional coding with the same rate and memory 2, 4 and 8 best d/sub free/ encoders. When turbo frames are very long, turbo coding with a channel interleaver gets better bit error rates (BER) than ordinary convolutional coding with a channel interleaver. When the frames are shorter, lower complexity convolutional coding is as good as turbo coding. It is shown by experiment that only after a certain critical frame size does turbo coding get better BER than convolutional coding and the length of this threshold is linearly dependent on the inverse of the fading bandwidth, 1/BT. The effect of the constituent encoders on the error performance is also tested. Memory 2, 4 and 6 constituent encoders are compared. For short to moderate turbo frame size, the memory 2 constituent encoder is as good as the memory 4 and better than the memory 6 encoder. For very long block-lengths, the memory 4 encoder is the best. The memory 6 encoder is always the worst.","PeriodicalId":136537,"journal":{"name":"2001 MILCOM Proceedings Communications for Network-Centric Operations: Creating the Information Force (Cat. No.01CH37277)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127677921","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}
Pub Date : 2001-10-28DOI: 10.1109/MILCOM.2001.985774
L. Hong, K. C. Ho
Modulation classification is a technique that automatically identifies the modulation type of a received signal. It has found a variety of military and commercial applications. In some practical cases such as signal interception, the intercepted signal is very weak and a long observation time is needed to maintain an acceptable probability of correct identification. This paper presents an algorithm using a two element antenna array receiver for BPSK and QPSK classification to increase the probability of correct classification for a short data record. The approach is to perform the generalized likelihood ratio test. The unknown phase shift between the two received signals due to the spatial separation of the antenna elements is estimated using maximum likelihood or linear least squares technique. It is then used in the likelihood ratio test for classification. Simulations show that the proposed classifier has high accuracy and is superior to the classifier that has only one received antenna.
{"title":"Modulation classification of BPSK and QPSK signals using a two element antenna array receiver","authors":"L. Hong, K. C. Ho","doi":"10.1109/MILCOM.2001.985774","DOIUrl":"https://doi.org/10.1109/MILCOM.2001.985774","url":null,"abstract":"Modulation classification is a technique that automatically identifies the modulation type of a received signal. It has found a variety of military and commercial applications. In some practical cases such as signal interception, the intercepted signal is very weak and a long observation time is needed to maintain an acceptable probability of correct identification. This paper presents an algorithm using a two element antenna array receiver for BPSK and QPSK classification to increase the probability of correct classification for a short data record. The approach is to perform the generalized likelihood ratio test. The unknown phase shift between the two received signals due to the spatial separation of the antenna elements is estimated using maximum likelihood or linear least squares technique. It is then used in the likelihood ratio test for classification. Simulations show that the proposed classifier has high accuracy and is superior to the classifier that has only one received antenna.","PeriodicalId":136537,"journal":{"name":"2001 MILCOM Proceedings Communications for Network-Centric Operations: Creating the Information Force (Cat. No.01CH37277)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120851030","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}
Pub Date : 2001-10-28DOI: 10.1109/MILCOM.2001.985990
M. Souryal, B. Vojcic, R. Pickholtz
In an ad hoc multihop CDMA network, fading can adversely affect the expected progress per hop of a packet. However, the effects of fading can be mitigated through route diversity, where a given source-destination pair has multiple possible paths through which to route packets. First, the distribution of the interference power is derived using a previously proposed model, and with Rayleigh fading the distribution is shown to be the same as for the non fading case except for a scaling factor. Expressions for the expected progress per hop are derived for the cases with and without next-hop route diversity. We find that the expected progress per hop in a Rayleigh fading channel can be significantly improved with low-order route diversity.
{"title":"Ad hoc, multihop CDMA networks with route diversity in a Rayleigh fading channel","authors":"M. Souryal, B. Vojcic, R. Pickholtz","doi":"10.1109/MILCOM.2001.985990","DOIUrl":"https://doi.org/10.1109/MILCOM.2001.985990","url":null,"abstract":"In an ad hoc multihop CDMA network, fading can adversely affect the expected progress per hop of a packet. However, the effects of fading can be mitigated through route diversity, where a given source-destination pair has multiple possible paths through which to route packets. First, the distribution of the interference power is derived using a previously proposed model, and with Rayleigh fading the distribution is shown to be the same as for the non fading case except for a scaling factor. Expressions for the expected progress per hop are derived for the cases with and without next-hop route diversity. We find that the expected progress per hop in a Rayleigh fading channel can be significantly improved with low-order route diversity.","PeriodicalId":136537,"journal":{"name":"2001 MILCOM Proceedings Communications for Network-Centric Operations: Creating the Information Force (Cat. No.01CH37277)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121328829","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}
Pub Date : 2001-10-28DOI: 10.1109/MILCOM.2001.985767
D. Gregg, W. Blackert, D. Heinbuch, D. Furnanage
Denial of service (DoS) attacks come in a variety of types and can target groups of users, individual users, or entire computer systems. With the ever-increasing reliance on networked information systems for command and control of military systems - not to mention communications infrastructures - relatively simple attacks that degrade or deny service can have devastating effects. The critical importance of protection from DoS attacks is well recognized by the DoD and in fact, the USA National Computer Security Center defines INFOSEC to include "measures and controls to protect infrastructure against denial of service". There are basically three levels of DoS attacks, growing both in sophistication and seriousness of attack effects. The simplest attack exploits errors and bugs in the design and source code of a network operating system. The second level of attack exploits known artifacts of a particular system implementation or protocol, often due to limited storage or capacity, to introduce delay, to saturate a system, or otherwise limit accessibility. The third and most damaging level of attack uses very specific features of the network protocol to mount the attack. These attacks are specifically designed to look like normal usage. We have modeled and validated five different DoS attacks. We have executed these attack models against a validated model of a target network whose architecture and stochastic behavior is varied for analysis purposes. We are currently conducting a systems analysis using these models and are looking across the protocol stack and target network for attack effects. This paper describes the analysis of one attack's effectiveness by varying the attack rate, server time out, and connection settings. Output from our model includes probability of denied service, delay and outage time, and correlations under attack and no attack conditions. Our objective is to characterize attack effects and to ultimately derive mitigation techniques and indications and warnings.
{"title":"Assessing and quantifying denial of service attacks","authors":"D. Gregg, W. Blackert, D. Heinbuch, D. Furnanage","doi":"10.1109/MILCOM.2001.985767","DOIUrl":"https://doi.org/10.1109/MILCOM.2001.985767","url":null,"abstract":"Denial of service (DoS) attacks come in a variety of types and can target groups of users, individual users, or entire computer systems. With the ever-increasing reliance on networked information systems for command and control of military systems - not to mention communications infrastructures - relatively simple attacks that degrade or deny service can have devastating effects. The critical importance of protection from DoS attacks is well recognized by the DoD and in fact, the USA National Computer Security Center defines INFOSEC to include \"measures and controls to protect infrastructure against denial of service\". There are basically three levels of DoS attacks, growing both in sophistication and seriousness of attack effects. The simplest attack exploits errors and bugs in the design and source code of a network operating system. The second level of attack exploits known artifacts of a particular system implementation or protocol, often due to limited storage or capacity, to introduce delay, to saturate a system, or otherwise limit accessibility. The third and most damaging level of attack uses very specific features of the network protocol to mount the attack. These attacks are specifically designed to look like normal usage. We have modeled and validated five different DoS attacks. We have executed these attack models against a validated model of a target network whose architecture and stochastic behavior is varied for analysis purposes. We are currently conducting a systems analysis using these models and are looking across the protocol stack and target network for attack effects. This paper describes the analysis of one attack's effectiveness by varying the attack rate, server time out, and connection settings. Output from our model includes probability of denied service, delay and outage time, and correlations under attack and no attack conditions. Our objective is to characterize attack effects and to ultimately derive mitigation techniques and indications and warnings.","PeriodicalId":136537,"journal":{"name":"2001 MILCOM Proceedings Communications for Network-Centric Operations: Creating the Information Force (Cat. No.01CH37277)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116477630","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}
Pub Date : 2001-10-28DOI: 10.1109/MILCOM.2001.985836
M. Chamberlain
The US government has developed and adopted a new military standard vocoder (MIL-STD-3005) algorithm called mixed excitation linear prediction (MELP) which operates at 2.4 kbps. The vocoder has good voice quality under benign error channels. However, when the vocoder is subjected to a HF channel with typical power output of a manpack radio (MPR), the vocoder speech quality is severely degraded. Harris has found that a 600 bps vocoder provides significant increase in secure voice availability relative to the 2.4 kbps vocoder. This paper describes a 600 bps MELP vocoder algorithm that takes advantage of the inherent inter-frame redundancy of the MELP parameters. Data is presented showing the advantage in both diagnostic acceptability measure (DAM) and diagnostic rhyme test (DRT) with respect to SNR on a typical HF channel when using the vocoder with a MIL-STD-188-110B waveform.
{"title":"A 600 bps MELP vocoder for use on HF channels","authors":"M. Chamberlain","doi":"10.1109/MILCOM.2001.985836","DOIUrl":"https://doi.org/10.1109/MILCOM.2001.985836","url":null,"abstract":"The US government has developed and adopted a new military standard vocoder (MIL-STD-3005) algorithm called mixed excitation linear prediction (MELP) which operates at 2.4 kbps. The vocoder has good voice quality under benign error channels. However, when the vocoder is subjected to a HF channel with typical power output of a manpack radio (MPR), the vocoder speech quality is severely degraded. Harris has found that a 600 bps vocoder provides significant increase in secure voice availability relative to the 2.4 kbps vocoder. This paper describes a 600 bps MELP vocoder algorithm that takes advantage of the inherent inter-frame redundancy of the MELP parameters. Data is presented showing the advantage in both diagnostic acceptability measure (DAM) and diagnostic rhyme test (DRT) with respect to SNR on a typical HF channel when using the vocoder with a MIL-STD-188-110B waveform.","PeriodicalId":136537,"journal":{"name":"2001 MILCOM Proceedings Communications for Network-Centric Operations: Creating the Information Force (Cat. No.01CH37277)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2001-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127111194","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：