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An adaptive multi-rate speech coder for digital cellular telephony

E. Paksoy, J. Carlos de Martin, A. McCree, C.G. Gerlach, A. Anandakumar, Wai-Ming Lai, V. Viswanathan
1999 1999 IEEE International Conference on Acoustics, Speech, and Signal Processing. Proceedings. ICASSP99 (Cat. No.99CH36258)  
The speech coders in each codec mode are based on the CELP algorithm operating at rates ranging from 11.85 kb/s down to 5.15 kb/s, where the lowest rate coder is a source controlled multi-modal speech  ...  The decoders monitor channel quality at both ends of the wireless link using the soft values for the received bits and assist the base station in selecting the codec mode that is appropriate for a given  ...  It uses a source-controlled multimodal CELP coder where each input speech frame is classified into one of two source coding modes based on a voiced/unvoiced decision.  ... 
doi:10.1109/icassp.1999.758095 dblp:conf/icassp/PaksoyMMGALV99 fatcat:yxl3hrobrja7pd7heilcx4mfuu

GSM Speech Coder Indirect Identification Algorithm

Rajko Svečko, Bojan Kotnik, Amor Chowdhury, Zdenko Mezgec
2010 Informatica  
This paper presents GSM speech coder indirect identification algorithm based on sending novel identification pilot signals through the GSM speech channel.  ...  Further, a noise reduction with spectral subtraction based on spectral smoothing is carried out.  ...  This paper presents GSM speech coder indirect identification based on sending novel pilot signals through GSM speech channel (Fig. 1) .  ... 
doi:10.15388/informatica.2010.306 fatcat:7uj3izernvaqhom6aoha47if7y

Modeling, estimating, and compensating low-bit rate coding distortion in speech recognition

N.B. Yoma, C. Molina, J. Silva, C. Busso
2006 IEEE Transactions on Audio, Speech, and Language Processing  
A solution to the problem of speech recognition with signals distorted by low-bit rate coders is presented in this paper.  ...  A model for the coding-decoding distortion, a HMM compensation method to include this model, and an EM-based adaptation algorithm to estimate this distortion are proposed here.  ...  King, CSTR/University of Edinburgh, Edinburgh, U.K., for having proofread this manuscript, and S.  ... 
doi:10.1109/tsa.2005.852994 fatcat:gfwfutwjrzd6fhlsyiuw63qrkq

Implementation of PCCD-OFDM-ASK Robust Data Transmission over GSM Speech Channel

Zdenko Mezgec, Amor Chowdhury, Bojan Kotnik, Rajko Svečko
2009 Informatica  
It is used to transmit the digital data over the speech channel of the mobile communication system GSM, as well as CDMA.  ...  The main key points of the proposed modulation schemes are: precise signal synchronization between the modulator and demodulator, signal energy independent operation, on line adaptation of frequency characteristics  ...  This coder belongs to the class of Regular Pulse Excitation -Long Term Predictionlinear predictive (RPE-LTP) coders.  ... 
doi:10.15388/informatica.2009.237 fatcat:77wm37xuwbgdll5g77as2tevai

Distortion-class modeling for robust speech recognition under GSM RPE-LTP coding

Juan M. Huerta, Richard M. Stern
2001 Speech Communication  
the relative combination of the two sources depending on the extent to which each class of phonemes is degraded by the coding process.  ...  We present a method to reduce the degradation in recognition accuracy introduced by full-rate GSM RPE-LTP coding by combining sets of acoustic models trained under dierent distortion conditions.  ...  Similar analyses of the eects of coding based on distortion categories can easily be applied to other types of closed-loop predictive coders regardless of their bit rates.  ... 
doi:10.1016/s0167-6393(00)00055-8 fatcat:idsgszl4k5av7ckaypbn5n3iuy

Security Aspects of the Cellular Communications

Metodi Popov
2000 Information & Security An International Journal  
GSM standard recommends that the bit of class 1 to be 182 and bits class II to be 78. IS-54 standard recommends that the bits of class I to be 77 and the bits of class 2 to be 82.  ...  Based on the discretion of the PLMN operator, the authentication key can be of any format and length.  ... 
doi:10.11610/isij.0405 fatcat:pbr6dt6y6vcrhozyaqgilbju4y

Soft Reconstruction of Speech in the Presence of Noise and Packet Loss

Farshad Lahouti, Amir K. Khandani
2007 IEEE Transactions on Audio, Speech, and Language Processing  
The proposed methodology is based on the classification of the signal domain and efficient approximation of the residual redundancy or the a priori transition probabilities.  ...  In this paper, we consider soft reconstruction of speech spectrum, in GSM Adaptive Multi-Rate and IS-641 vocoders, transmitted over a channel disturbed with noise and/or packet loss.  ...  In [28] , based on a Gaussian Mixture Modelling of the probability distribution of the LSF parameters in GSM-AMR, a loss concealment algorithm is proposed which estimates the missing splits based on the  ... 
doi:10.1109/tasl.2006.876874 fatcat:pr4skw2pu5hhnjkdh4msy76tgi

Study and Performance of AMR Codecs for GSM
IJARCCE - Computer and Communication Engineering

2014 IJARCCE  
Adaptive Multi Rate is one of the techniques that neutralize the deleterious effect of the channel on speech.  ...  The quality of speech at receiver end decides by channel conditions. Modelling a channel is a multifarious task. A number of techniques are adopted to alleviate the effect of the channel.  ...  Accordingly CELP is now used as a generic term for a particular class of vocoders or speech codecs and not a particular codec.  ... 
doi:10.17148/ijarcce.2014.31006 fatcat:pgmtj6gub5hnnansslmnpkmyji

A Reconfigurable Baseband Transmitter for Adaptive Image Coding

Amor Nafkha, Renaud Seguier, Jacques Palicot, Christophe Moy, Jean-Philippe Delahaye
2007 2007 16th IST Mobile and Wireless Communications Summit  
A Cognitive device will be able to reconfigure itself to adapt its baseband radio transmitter to the required bit rate of the coding scheme.  ...  In this paper, a such platform able to adapt the Radio Access Technology (RAT) to the image coding scheme is described.  ...  are data-flow oriented [6] , our approach is based on a data-path model.  ... 
doi:10.1109/istmwc.2007.4299191 fatcat:yk7ddzotzzedrms7ns7owctcva

Investigating the performance of various vocoders for a fair scheduling algorithm in WiMAX

B. Kaarthick, V. J. Yeshwenth, N. Nagarajan, Rajeev
2009 2009 First Asian Himalayas International Conference on Internet  
The performance of Voice over IP services depends on a proper scheduling algorithm combined with a proper Voice encoder scheme. The contribution of this work is two fold.  ...  With the due rapid deployment of WiMAX, there would be a growing demand for efficient support of voice applications.  ...  We compare the performance of different Vocoders based on MOS, end to end delay and jitter. Based on the simulation results, we suggest a suitable vocoder that is best suited for the algorithm.  ... 
doi:10.1109/ahici.2009.5340356 fatcat:pbwlohtvbfaztf2t6qszm55f3u

Voice Quality Estimation in Combined Radio-VoIP Networks for Dispatching Systems

Jiri Vodrazka, Jan Kucerak
2016 Advances in Electrical and Electronic Engineering  
This article seeks to contribute voice quality modelling assessment and planning for dispatching communication systems based on Internet Protocol (IP) and private radio networks.  ...  theoretically and practically mastered for common voice communication systems, especially for the public fixed and mobile telephone networks including Next Generation Networks (NGN -internet protocol based  ...  Acknowledgment This work was supported by the Grant of the Technology Agency of the Czech Republic, No.  ... 
doi:10.15598/aeee.v14i4.1832 fatcat:jq6pds3hubg2lfeyd3wqukv7f4

Performance Evaluation for GSM Receiver Using Software Defined Radio

Asmaa Mohammed, Heba Asem, Hatem Yousry, Abdelhalim Zekry
2015 International Journal of Engineering Trends and Technoloy  
System of Mobile communications (GSM) by altering the physical layer behavior through changes in its software.  ...  Then the performance of the receiver has been analyzed by comparing the input and output waveforms with /without FH. Finally a comparison of the simulation results is presented and discussed.  ...  hardware modules to build open system platform based on software.  ... 
doi:10.14445/22315381/ijett-v30p262 fatcat:5223p6e2wjfutcjsxwvj7g7yru

An Architecture for a Next Generation VoIP Transmission System

Chr. Hoene, K. Clüver, J. Weil
2007 PIK - Praxis der Informationsverarbeitung und Kommunikation  
The speech codecs include ITU G.711, ITU G.729, Speex, ETSI GSM-EFR, 3GPP AMR, 3GPP AMR-WB, 1 These statements are based on a comparison of the specifications of commercial phones.  ...  The second one is based on the observation that low bit rate is not the only transmission parameter that is of importance in a packetized network.  ... 
doi:10.1515/piko.2007.76 fatcat:mds55buowvf67hidgtwgckfzva

Comparison of two speech content authentication approaches

Chung-Ping Wu, C.-C. Jay Kuo, Edward J. Delp III, Ping W. Wong
2002 Security and Watermarking of Multimedia Contents IV  
The first scheme is based on content feature extraction that is integrated with CELP speech coders to minimize the total computational cost.  ...  Speech content authentication, which is also called speech content integrity or tamper detection, protects the integrity of speech contents instead of the bitstream itself.  ...  The model-based speech coders could generate an SNR value as low as 1 or 2 dB, such as the case of GSM-AMR.  ... 
doi:10.1117/12.465272 dblp:conf/sswmc/WuK02 fatcat:g33zh3o73nhdnbr2wly7wsxqky

An Improved Speech and Channel Coding for GSM System [chapter]

Dariusz Godyń, Dominik Rutkowski
2000 Personal Wireless Communications  
In the paper an improved speech and channel coding/decoding for the GSM system has been described.  ...  coding/decoding in the presence of fading and noise. 1.  ...  FULL-RATE CODING WITH REDUCED BIT RATE The source coding of speech in GSM system is based on the digital model of a natural mechanism of speech signal generation.  ... 
doi:10.1007/978-0-387-35526-9_7 fatcat:6kvpo3wdbrexjc4pnjpawbmkvu
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