{"title":"Time-frequency spread OFDM/FHMA","authors":"K. Hamaguchi, L. Hanzo","doi":"10.1109/VETECS.2003.1207827","DOIUrl":null,"url":null,"abstract":"A combined scheme based on orthogonal frequency-division multiplexing and frequency-hopped multiple access (OFDM/FHMA) is proposed, in which the transmitted data is spread over both the time and frequency axes without expanding the bandwidth. The OFDM system advocated employs the Walsh-Hadamard transform (WHT) for spreading the data in the frequency domain and weights the received signal by the estimated signal-to-interference ratio (SIR) for the sake of reducing the effects of interference. The performance recorded, when communicating over an interference-limited channel suggests that the achievable BER improvement is as much an order of magnitude to that of an OFDM/FHMA scheme dispensing with WHT.","PeriodicalId":272763,"journal":{"name":"The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring.","volume":"12 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2003-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"3","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The 57th IEEE Semiannual Vehicular Technology Conference, 2003. VTC 2003-Spring.","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/VETECS.2003.1207827","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 3
Abstract
A combined scheme based on orthogonal frequency-division multiplexing and frequency-hopped multiple access (OFDM/FHMA) is proposed, in which the transmitted data is spread over both the time and frequency axes without expanding the bandwidth. The OFDM system advocated employs the Walsh-Hadamard transform (WHT) for spreading the data in the frequency domain and weights the received signal by the estimated signal-to-interference ratio (SIR) for the sake of reducing the effects of interference. The performance recorded, when communicating over an interference-limited channel suggests that the achievable BER improvement is as much an order of magnitude to that of an OFDM/FHMA scheme dispensing with WHT.