DataMappingontoSpeech-like Signal to Transmission overtheGSM VoiceChannel
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Oneofthemostimportant objectives inmobile communications channel andthenreaches thesecond communication systems is securevoiceand data GSM handset. Thereceived waveformfromsecond communication (including text, picture, video andvoice) esp. handset isdemodulated, decrypted andfinally decoded inhighbitrates. Inthis paper, anewprocedure isproposed (3) inwhichtheintended dataorvoiceisencrypted and modulated ontospeech-like waveforms. Themodulated Theovllsysteockdiagrm lss n in waveforms aretransmitted overtheglobal system formobile Fg1.uecto lw raeqof speechaningsuc communications (GSM) voice channel andthen demodulatedcommunications, we require modemshavingdata anddecrypted atthereceiver. Wepropose anappropriate transfer capability withlowbitrates. Asaresult, based modelfor theGSMAFull Rate(FR) speech codec bymapping ontheproposed methodinthispaper, anappropriate data onto thefundamental parameters related toformants in modemispresented. However, insomerecent works aspeech-like waveform including phases, frequencies and byKatugampala reported in(3), codebooks including pitch frequencies. Theproposed modelhasbeenevaluatedthevalues ofspeech-like waveform parameters are fora GSM-to-GSMconnection. Conducting different definedincluding pitchfrequency, LineSpectral simulations weobserved that theproposed approach resultsFrequencies (LSF)coefficients andframeenergyin ina biterrorrate(BER)of0.020o whenSignal-to-Noise Ratio(SNR) is15dBina 1.5kbps channeL Asa result,modulator side. Nextthese parameters areusedfor proposed method canbeconsidered asafavorable choice for waveforms synthesis. Finally, theencrypted dataare robustness toadditive noise.