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IEICE Transactions. 01/2011; 94-B:350-354.
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ABSTRACT: A 4+12+16 amplitude phase shift keying (APSK) modulation outperforms other 32-APSK modulations such as rectangular or cross 32-quadrature amplitude modulations (QAMs) which have a high peak to average power ratio that causes non-negligible amplitude modulation to amplitude modulation (AM/AM) and amplitude modulation to phase modulation (AM/PM) distortions when the signal is amplified by a high-power amplifier (HPA). Thus, this modulation scheme has been recommended as modulation scheme in the digital video broadcasting-Satellite2 (DVB-S2) standard. In this paper, we present a new bits-to-symbol mapping to improve a bit error rate (BER) for a 4+12+16 APSK signal in a nonlinear satellite channel and analyze the BER.
Digital Telecommunications, 2009. ICDT '09. Fourth International Conference on; 08/2009
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IEICE Transactions. 01/2009; 92-B:3384-3388.
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ABSTRACT: In an orthogonal frequency division multiplexing (OFDM) system, in-phase and quadrature (I/Q) imbalances generated in the analog front-end introduce inter-channel interference (ICI) and, consequently, error performance degradation. In this paper, a general and exact expression involving the two-dimensional (2-D) Gaussian Q-function for symbol error probability of MPSK-OFDM signal with I/Q imbalances is provided. The effect of I/Q imbalances on the error performance and the distribution of an additive white Gaussian noise (AWGN) on the signal constellation are also exactly analyzed.
Communication Systems, 2008. ICCS 2008. 11th IEEE Singapore International Conference on; 12/2008
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IEICE Transactions. 01/2008; 91-B:4030-4033.
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ABSTRACT: I/Q unbalances which are generated by a non-ideal component of receiver are an inevitable physical phenomenon and lead to performance degradation in implementation of a practical communication system. In this paper, we provide a general closed-from expression for the bit error rate (BER) of hierarchical M-ary phase shift keying (H-MPSK) with I/Q phase and amplitude unbalances, and analyze the effect of I/Q unbalances on the BER performance over an additive white Gaussian noise (AWGN) channel.
Internet, 2006 2nd IEEE/IFIP International Conference in Central Asia on; 10/2006
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ABSTRACT: The I/Q unbalance which is generated by a non-ideal component is an inevitable physical phenomenon and leads to performance degradation when we implement a practical two-dimensional (2-D) modulation system. This paper provides an exact and general expression involving the 2-D Gaussian Q-function for the SER/BER of arbitrary 2-D signaling with I/Q amplitude and phase unbalances over an additive white Gaussian noise (AWGN) channel by using the coordinate rotation and shifting technique. Through Monte Carlo simulations we verify our expression provided here for various 16-Quadrature Amplitude Modulation (QAM) circular constellations.
Advanced Communication Technology, 2006. ICACT 2006. The 8th International Conference; 03/2006
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IEICE Transactions. 01/2006; 89-B:3356-3362.
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IEICE Transactions. 01/2006; 89-B:1675-1677.
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ABSTRACT: Recently, we provided closed-form expressions involving two-dimensional (2-D) joint Gaussian Q-function for the symbol error rate (SER) and bit error rate (BER) of an arbitrary 2-D signal with I/Q unbalances over an additive white Gaussian noise (AWGN) channel [1]. In this paper, we extend the expressions to Nakagami-m fading channels. Using Craig's representation of the 2-D Gaussian Q-function, we derive an exact and general expression for the error probabilities of arbitrary 2-D signaling with I/Q phase and amplitude unbalances over Nakagami-m fading channels.
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ABSTRACT: Recently, we provided closed-form expressions involving two-dimensional (2-D) joint Gaussian Q-function for the symbol error rate (SER) and bit error rate (BER) of an arbitrary 2-D signal with I/Q unbalances over an additive white Gaussian noise (AWGN) channel [1]. In this letter, we extend the expressions to Nakagami- m fading channels. Using Craig representation of the 2-D joint Gaussian Q-function, we derive an exact and general expression for the error probabilities of arbitrary 2-D signaling with I/Q phase and amplitude unbalances over Nakagami- m fading channels.
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ABSTRACT: Orthogonal frequency division multiple access (OFDMA) allows multi-user to make use of the same bandwidth as the single-user OFDM for data transmission. This paper considers resource allocation algorithm which supports the user throughput fairness and quality of service (QoS) in the fixed relay based cellular system with TDD-OFDMA. By measuring the current level of user requirement and allocating remaining subcarriers to the user in a poor channel condition, the proposed algorithm can improve the user throughput fairness without large amount of system throughput losses.
Digital Telecommunications, 2008. ICDT '08. The Third International Conference on;
