发明名称 AN FFT-BASED MULTITONE DPSK MODEM
摘要 A system and a method for transmitting coded information bits using multitone techniques on a frame-by-frame basis. For transmission, coded informat ion bits are mapped into differential phase signals and absolute phase signals are genera ted based on differential phase signals. N complex symbols are then generated and inverse discrete Fourier transformed into N complex, time-domain samples, which are augmented wit h a cyclic prefix and suffix. The augmented N complex, time-domain samples are then separated into two real samples and converted into first and second baseband sig nals. The first and second baseband signals are impressed into quadrature carrier componen ts to form in-phase and quadrature signal components which are combined into an RF signal p rior to transmission. For reception, a received RF signal is non-coherently quadrature demodulated into first and second quadrature baseband signals. First and second quadrature sample sequences are generated by sampling the quadrature baseband si gnals in parallel. The added cyclic prefix and suffix are discarded, and N complex number s are generated from the first and second quadrature (real) sample sequences. N channe l-weighted tones are generated by performing a discrete Fourier transform on the N complex numbers. N phase difference signals are generated which are demapped into coded information bits according to a predetermined phase constellation.
申请公布号 CA2213559(A1) 申请公布日期 1998.09.04
申请号 CA19972213559 申请日期 1997.08.21
申请人 AT&T CORP. 发明人 JAISINGH, GOPAL K.;HO, JIN-MENG
分类号 H04L27/34;H04J11/00;H04L27/18;H04L27/26;(IPC1-7):H04L27/18 主分类号 H04L27/34
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