1997 · 41 citations · 0 references
EngineeringComputer ScienceElectrical EngineeringDigital CommunicationInformation TheoryWireless CommunicationsCommunication NetworksDigital Signal ProcessingInterference ManagementModulationMultiple Access TechniquesSpread Spectrum CommunicationDynamic RangeFrequency Domain ProcessingHuffman CodingSignal Spreading CodesSpread Spectrum ModulationSpreading Codes
The paper contains an analysis of the basic criteria for the selection of spreading sequences for the multi-carrier CDMA (MC-CDMA) systems with spectrum spreading in the frequency domain. It is shown that the time-domain crosscorrelation function between the spreading sequences is not a proper interference measure for the asynchronous MC-CDMA users. Therefore the spectral correlation function is introduced and, together with the peak-to-average power ratio (PAPR) and the dynamic range of the corresponding multi-carrier waveforms, is used for the evaluation of MC-CDMA sequences. Some well-known classes of sequences, such as Walsh and Gold sequences, as well as orthogonal Gold and Zadoff-Chu (1972) sequences, are evaluated with respect to the aforementioned basic criteria. It is also shown that the multi-carrier spread spectrum waveforms based on the (multilevel) Huffman sequences have the lower PAPR than a single sine wave.