Results 181 to 190 of about 10,809 (212)

Trellis-coded 8PSK with embedded QPSK

IEEE Journal on Selected Areas in Communications, 1989
A coded eight-phase-shift-keying (C8PSK) method is described that is characterized by a quaternary phase-shift-keyed signal embedded in the modulated sequence. This method is a double-trellis-coded modification of the well-known C8PSK and is referred to as MC8PSK. Five coded bits are generated from four user bits in a single coding step and then mapped
Manfred Bertelsmeier, Günther Komp
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A New Approach to QPSK: Mechanism and Implementation

2007 IEEE Wireless Communications and Networking Conference, 2007
The work reported in this paper serves two purposes. First, an alternative comprehensive approach is proposed for the understanding of the mechanism behind QPSK. This focuses on how a QPSK modulator decides to represent each pair of to be transmitted bits by which of its four possible phase shifts.
Ali Abuelmaatti, Iain Thayne, Steve Beaumont   +2 more
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2018
In this paper, we propose a frame synchronization scheme for QPSK modulation based on binary sequences of even length with an ideal autocorrelation function. All binary synchronous sequences of length N = 8 with the idealness of the autocorrelation function are analytically found in the study.
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On the bit-error probability of differentially encoded QPSK and offset QPSK in the presence of carrier synchronization

IEEE Transactions on Communications, 2006
We investigate the differences between allowable differential encoding strategies and their associated bit-error probability performances for quadrature phase-shift keying (QPSK) and offset QPSK modulations when the carrier demodulation reference signals are supplied by the optimum (motivated by maximum a posteriori estimation of carrier phase) carrier-
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New approach for QPSK modulation

IEEE VTS 53rd Vehicular Technology Conference, Spring 2001. Proceedings (Cat. No.01CH37202), 2002
QPSK modulation is usually applied to a baseband signal, and the modulated signals are converted to an RF signal for transmission. Direct QPSK modulation at radio frequency has become increasingly needed for lower costs in commercial applications. A new QPSK modulation method for RF signals is reported.
null Liu Xiaoli, null Law Choi Look, null Shen Zhongxiang, S. Aditya, null Qian Cheng, null Sun Zhongliang   +5 more
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Implementation of a QPSK system on FPGA

2011 IEEE 9th International Symposium on Intelligent Systems and Informatics, 2011
The paper presents the design of a QPSK digital communication system and its implementation on FPGAs. The simulations of the system were made in Matlab/Simulink environment and System Generator, a tool used for FPGA designs. The system is made up of two Spartan 3E Starter Kit boards.
S.O. Popescu, A.S. Gontean, D. Ianchis
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A fast algorithm for maximum likelihood detection of QPSK or pi /4-QPSK sequences with unknown phase

[1992 Proceedings] The Third IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, 2003
Maximum likelihood sequence detection (MLSD) of differentially encoded MPSK uses a joint decision on N symbols to achieve a performance gain over conventional 2 symbol differential detection. This paper gives a fast (optimum) algorithm to implement MLSD; the number of operations per N symbol block is of order N log/sub 2/ N.
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Error Probability Performance of Unbalanced QPSK Receivers

IEEE Transactions on Communications, 1978
Summary: A simple technique for calculating the error probability performance and associated noisy reference loss of practical unbalanced QPSK receivers is presented. The approach is based on expanding the error probability conditioned on the loop phase error \(\varphi\) in a power series in \(\varphi\) and then, keeping only the first few terms of ...
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Fuzzy Model of QPSK and QAM Modulation

2011
In the paper, a concept of Additive Fuzzy Noise (AFN) channel is introduced. The theoretical equations are derived for Bit Error Rate (BER) and Symbol Error Rate (SER) with some digital modulation scheme in AFN channel. Following modulation are considered: Binary Phase Shift Keying (BPSK), Binary Frequency Shift Keying (BFSK), Pulse Amplitude ...
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Analysis of the factors that affect QPSK

2011 International Conference on Consumer Electronics, Communications and Networks (CECNet), 2011
In the QPSK modulation and demodulation process, the signal will be affected by some non-ideal factors, in this paper, these non-ideal factors were analyzed. This paper considers the magnitude imbalance, phase imbalance and phase noise factors. We will study the QPSK constellation to analysis the amplitude imbalance and phase imbalance. About the phase
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