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Channel estimation is one of key problems in IEEE 802.16e Orthogonal Frequency Division Multiplexing Access (OFDMA) downlink system. Minimum Mean Square Error (MMSE) channel estimation has been known as a superior performance channel estimation. However, this algorithm has high computational complexity. In this paper, we present low complexity(More)
Channel estimation is one of key problems in IEEE 802.16e Orthogonal Frequency Division Multiplexing Access (OFDMA) downlink system. Minimum Mean Square Error (MMSE) channel estimation has been known as a superior performance channel estimation. However, this algorithm has high computational complexity. In this paper, we present low complexity(More)
Based on IEEE 802.11 standard, frequencies of WLAN are: 2.4-2.474 GHz, 5.15-5.35 GHz, 5.475-5.725 GHz, and 5.725-5.825 GHz. Based on WiMAX Forum standard, two major band on certification profile for Fixed WiMAX (band 3.5 GHz and 5.8 GHz) and Mobile WiMAX comprises four frequencies, band 2.3 GHz, 2.5 GHz, 3.3 GHz and 3.5 GHz. At this research, design and(More)
This paper describes a successive multiuser detection technique for Direct Sequence Code Division Multiple Access (DS-CDMA) systems. In conventional CDMA system, single-user detection is employed, so that the interference between users or multiple access interference (MAI) component is considered as noise, which contributes to the statistics of detection(More)
This paper proposes variable step closed loop power control algorithm combined with space diversity to improve the performance of High Altitude Platforms (HAPs) communication at low elevation angle using Code Division Multiple Access (CDMA). In this contribution, we first develop HAPs channel model which is derived from experimental measurement. From our(More)
⎯ This paper describes the performance evaluation of fixed step closed loop power control algorithm in a novel wireless channel that is called High Altitude Platforms (HAPs). This new wireless delivery method is proposed as a complementary system in providing the next generation services in which the technology basically employs CDMA. In HAPs communication,(More)
We proposed a new method for timing estimation in cognitive radio systems under a fractional bandwidth (FBW) scenario. A conventional timing estimation based on autocorrelation suffering performance reduction caused by interference and multipath channel distortion. The proposed method is developed based on normalized 4-th order moment for symmetric(More)
Long Term Evolution Advanced (LTE-A) is a promising technology to achieve peak data rate of up to 1 Gbit/s in the downlink and 500 Mbit/s in the uplink. Because adjacent cells employs the same frequency in universal frequency reuse scheme, interference between adjacent cells may degrade the bit rate, particularly at the cell edges. Inter-Cell Interference(More)