error symbol
3.The simulation results show that if smart antenna is utilized to suppress multipath and the synchronization error between users is limited in 3/8 chip period, the symbol error rate (SER) performance approaches single user bound (SUB) and spectral efficiency amounts to 4bit/s/Hz, after the proposed scheme is applied.
5.Based on the single-carrier frequency domain equalizer(SC-FDE)approach providing immunity of inter-symbol interference(ISI),a novel frequency domain balanced structure for ultra-wideband system was proposed. The optimal frequency domain balance algorithm based on minimum mean-square error(MMSE) estimation wais introduced.
6.After analyzing the symbol structure of pulse position modulation (PPM), digital pulse interval modulation (DPM) and dual-header pulse interval modulation(DH-PIM) in detail, the average transmission power and bandwidth efficiency are analyzed. On the meantime, the slot error rate is also analyzed on the given model.
7.In multipath fading channel, the bit error rate (BER) performance of orthogonal frequency division multiplexing (OFDM) system using frequency domain differential detection (FDDD) is analyzed, the closed form expression of BER performance of FDDD is obtained. The results of analysis and simulation indicate that BER performance of FDDD is always affected by inter-symbol interference (ISI), but in different channel environments, BER performance of FDDD is influenced by ISI to different extend.

