Bit Error Rate Performance (bit + error_rate_performance)

Distribution by Scientific Domains
Engineering100%

Selected Abstracts

Performance analysis of adaptive receivers for DS/CDMA communication systems

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 12 2008
Fang-Biau Ueng
Abstract Both intersymbol interference (ISI) and multiple-access interference (MAI) are the important issues in code division multiple access (CDMA) multiuser communication systems. The step size of the traditional least-mean-square (LMS) adaptive receivers must be substantially adjusted to overcome the effect due to different channel responses or different numbers of active users. The normalized-LMS (NLMS) algorithm can automatically manipulate the adjustment to avoid the problem just discussed. This paper proposes the symbol-based interference rejection filter with NLMS algorithm and derives both finite impulse response (FIR)- and infinite impulse response (IIR)-type algorithms. We also derive the optimal step sizes and minimum mean-square errors (MSEs) for both the FIR and IIR symbol-based receivers. The complexity of our proposed FIR receiver is lower than that of the conventional chip-based receivers. In addition, it is shown that the bit error rate performance of our proposed symbol-based receivers is superior to conventional one in the simulations. Simulations also show the correctness of our theoretical analysis of minimum MSE. Copyright © 2008 John Wiley & Sons, Ltd. [source]

QPSK differential space time coding on different unitary matrices sets and initializations

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 9 2006
Jia Hou
Abstract This paper investigates a distinct set of complex unitary matrices for differential space time coding by using QPSK modulation. The numerical results show that the proper selection of the initial transmission matrix and the set of unitary matrices can efficiently improve the bit error rate performance, especially for the antennas correlated fading channel. The computer simulations are evaluated over slow and fast Rayleigh fading channels. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Dual diversity combining and decision feedback equalizer in indoor millimetre-wave channel

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 8 2002
Chien-Ching Chiu
Abstract Wideband communication characteristics of wireless indoor millimetre-wave channel for arched and rectangular buildings are investigated. The impulse responses of arched and rectangular buildings for any transmitter,receiver location are computed by shooting and bouncing ray/image (SBR/Image) techniques. By using the impulse responses of these multipath channels, the impact of shapes of building is presented and the bit error rate performance of binary phase shift keying (BPSK) system with phase and timing recovery circuits are also calculated. Moreover, dual space antenna diversity technique and decision feedback equalizer (DFE) with four forward and three feedback taps are used to combat the multipath fading. Numerical results show that the mean root mean square (rms) delay spread for the arched building is smaller than that for the rectangular building. In addition, it is also found that the transmission rate can be up to 20 Mbps for indoor millimetre-wave channel of these two buildings by using dual space diversity and DFE. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Analyzing GPS signals to investigate path diversity effects of non-geostationary orbit satellite communication systems

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS AND NETWORKING, Issue 6 2002
Hsin-Piao Lin
Abstract The concept behind path diversity is that a user who can access several satellites simultaneously will be able to communicate more effectively than a user who could only access one. The success of this method depends on the environment, the satellite constellation, and diversity combining technology. This paper explores the path diversity effects of non-geostationary orbit (NGO) satellite personal communication services, for different degrees of user mobility, under various scenarios, using the constellation of the global positioning system (GPS). Measurements are taken near downtown Taipei. Three types of mobilities (fixed-point, pedestrian, and vehicular) are examined, and the switch diversity and maximum ratio combining method are applied to determine the path diversity gain and calculate bit error probability. The error probability performance of applying diversity schemes in coherent binary phase shift keying (BPSK) and non-coherent differential phase shift keying (DPSK) modulations over Rician fading channels are also analysed and evaluated by using the characteristic function method. The results show that fading can be significantly reduced and diversity greatly increased. A significant diversity gain and improvement in bit error rate (BER) can be expected in all cases by simply applying switch diversity scheme. Besides, for the maximum ratio combining method, the results imply that summing two satellite signals suffices to increase diversity and improve the bit error rate performance. Copyright © 2002 John Wiley & Sons, Ltd. [source]

A new ICI mitigation method with generalized data-allocation for OFDM systems

INTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 4 2010
Jiun-Ming Wu
Abstract This paper describes an ICI mitigation method based on the generalized data-allocation of (1, ,,) for orthogonal frequency division multiplexing systems. To improve the performance of the ICI mitigation for the higher-frequency offset, we propose an efficient search algorithm to generate the sub-optimal parameter , for maximizing the carrier-to-interference ratio (CIR). The CIR and bit error rate performances of the proposed method were derived in this paper. The performances with different carrier frequency offset scenarios were evaluated by computer simulations. According to the simulation results, the performance of the proposed ICI mitigation scheme is better than that of the conventional ICI self-cancellation scheme and is nearly the same as that of the ICI self-cancellation scheme for the optimal parameter ,. Additionally, the proposed ICI mitigation scheme has a dramatically reduced hardware complexity in comparison with the ICI self-cancellation scheme for the optimal parameter ,. Copyright © 2009 John Wiley & Sons, Ltd. [source]