The bandwidth efficient modulation format Offset-QPSK (OQPSK) is implemented up to now merely in mobile radio systems which do employ spread spectrum techniques, i.e., it is not used in narrow band systems. This is due to the fact, that, in spite of its reduced performance degradation in ...
an application scheme of free space optical communication technology in INMARSAT, and propose a 1.12 Tbit/s coherent free-space optical (FSO) communication system based on wavelength division multiplexing (WDM) and polarization-multiplexing quadrature phase shift keying (PM-QPSK) modulation technology. ...
自动调制识别技术可以用于排除通信系统中的非法用户及其干扰,是保证合法通信的关键措施之一.选取了几种典型的调制方式MFSK,MASK,BPSK,QPSK,OFDM,通过分析其时域特征,... 陈美,朱琦 - 《重庆邮电大学学报(自然科学版)》 被引量: 14发表: 2009年 基于优化RBF神经网络的集成算法及其在调制识别中的应用 首先通过模拟退...
to complete the recognition process.The modulation types clas- sifted by this recognizer are 2PSK,QPSK,8PSK,2FSK,4FSK,8FSK,2ASK,4ASK and 16QAM.Simulation results show that the average rate of accurate classification is over 97% at a signal-to-noise(SNR)of 5dB,and more,the system is ...
Robustness analysis shows that introducing a mixed modulation scheme in addition to QPSK and 8PSK in the adaptive modulation scheme is unnecessary, and HARQ with adaptive modulation is insensitive to deviations from the optimal threshold, thus facilitating its implementation. Copyright 2004 John Wiley &...
The modulation used was OFDM (WiMAX 802.16-2004) MMDS band, 1.5MHz BW, with 256 size FFT and 1 burst at QPSK 3/4. Figure 9 shows how the peak-to-peak ripple decreases with increasing external filter capacitance value. Also shown is how the RF pulse response will have longer rise and ...
This paper presents the design of a QPSK/16-QAM downstreams receiver chip. The proposed chip consists of a blind equalizer, a timing recovery block and a c... KH Park,DK Shin,JS Lee,... 被引量: 0发表: 2000年 ASIC-based spectrally efficient modulation for wireless wideband data transmiss...
The performance of the optical SOQPSK modulated system is evaluated and compared with those of quadrature phase shift keying (QPSK) and offset QPSK (OQPSK) modulation systems via simulation, in terms of spectral efficiency, receiver sensitivity and density DWDM transmission performance. Simulations show...
For CMBFA and NCMBFA, the bit error rate performance of the network for BPSK, QPSK, and 64-QAM modulation schemes are analyzed. The performance metrics of the packet received, delay and the average jitter of CMBFA and NCMBFA are compared. Simulation results show clearly that CMBFA gives ...
(QPSK) symbols may be mapped to each REG. The PDCCH can be transmitted using one or more CCEs, depending on the size of the downlink control information (DCI) and the channel condition. There can be four or more different PDCCH formats defined in LTE with different numbers of CCEs (e.g...