{"title":"An adaptive modulation scheme for simultaneous voice and data transmission over fading channels","authors":"Mohamed-Slim Alouini, X. Tang, A. Goldsmith","doi":"10.1109/VETEC.1998.686378","DOIUrl":null,"url":null,"abstract":"We propose a new adaptive modulation technique for simultaneous voice and data transmission over fading channels, and study its performance. The proposed scheme takes advantage of the time-varying nature of fading to dynamically allocate the transmitted power between the inphase (I) and quadrature (Q) channels. It uses fixed-rate binary phase shift keying (BPSK) modulation on the Q channel for voice, and variable-rate M-ary amplitude modulation (M-AM) on the I channel for data. For favorable channel conditions most of the power is allocated to high rate data transmission on the I channel. The remaining power is used to support the variable-power voice transmission on the Q channel. As the channel degrades the modulation gradually reduces its data throughput and reallocates most of its available power to insure a continuous and satisfactory voice transmission. The scheme is intended to provide a high average spectral efficiency for data communications while meeting the stringent delay requirements imposed by voice. We present closed-form expressions as well as numerical and simulation results for the outage probability, average allocated power, achievable spectral efficiency, and average bit-error-rate for both voice and data, transmission over Nakagami-m (1960) fading channels. We also discuss the features and advantages of the proposed scheme.","PeriodicalId":335954,"journal":{"name":"VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151)","volume":"86 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"1998-05-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"160","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"VTC '98. 48th IEEE Vehicular Technology Conference. Pathway to Global Wireless Revolution (Cat. No.98CH36151)","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/VETEC.1998.686378","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 160
Abstract
We propose a new adaptive modulation technique for simultaneous voice and data transmission over fading channels, and study its performance. The proposed scheme takes advantage of the time-varying nature of fading to dynamically allocate the transmitted power between the inphase (I) and quadrature (Q) channels. It uses fixed-rate binary phase shift keying (BPSK) modulation on the Q channel for voice, and variable-rate M-ary amplitude modulation (M-AM) on the I channel for data. For favorable channel conditions most of the power is allocated to high rate data transmission on the I channel. The remaining power is used to support the variable-power voice transmission on the Q channel. As the channel degrades the modulation gradually reduces its data throughput and reallocates most of its available power to insure a continuous and satisfactory voice transmission. The scheme is intended to provide a high average spectral efficiency for data communications while meeting the stringent delay requirements imposed by voice. We present closed-form expressions as well as numerical and simulation results for the outage probability, average allocated power, achievable spectral efficiency, and average bit-error-rate for both voice and data, transmission over Nakagami-m (1960) fading channels. We also discuss the features and advantages of the proposed scheme.