Fig 6 - available via license: Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International
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Directivity characteristics against each signal sources of conventional TDL array antenna. Arrival angle θ 0 = θ 1 = θ 2 = 0 in degree. (Maximum gain is normalized to 0 dB.)
Source publication
This paper provides a space temporal interference cancellation method for ultra wide-band (UWB) communication systems based on combination of tapped delay line array antenna and orthogonal matched filter. In order to reduce the interference from the other system using overlapping frequency band, space domain signal processing such as an array anten...
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Non-Orthogonal Multiple Access (NOMA) and Heterogeneous Network (HetNet) are two significant and promising enabling techniques to further improve overall system performance for next-generation mobile communication systems. In this study, we develop a novel NOMA HetNet through applying NOMA technique to both macrocell and small-cell of conventional...
Citations
... Another problem is that the spreading sequence of each user is unknown in a wireless ad hoc network [10][11][12][13]. The orthogonal matched filter (OMF) has been applied to solve this problem [14][15][16][17]. The OMF cancels interference by generating and subtracting a replica of the interference signal contained in the received signal [14][15][16][17]. ...
... The orthogonal matched filter (OMF) has been applied to solve this problem [14][15][16][17]. The OMF cancels interference by generating and subtracting a replica of the interference signal contained in the received signal [14][15][16][17]. For example, an interference cancellation method using concatenated spreading sequences and a layered OMF to support different period spreading sequences is proposed [14]. ...
... For example, an interference cancellation method using concatenated spreading sequences and a layered OMF to support different period spreading sequences is proposed [14]. A space temporal interference cancellation method for ultra-wideband (UWB) communication systems based on the combination of a tapped delay line array antenna and an OMF is provided since impulse radio UWB does not have a carrier signal [15]. An inter-user and inter-system interference mitigation method using a combination of an orthogonal pulse shape modulation and an OMF detector is proposed [16]. ...
This research provides a novel extended orthogonal matched filter (EOMF) structure that supports multiuser detection. In addition, this structure is designed to suppress increases in computational complexity and circuit scale. In coming years, the number of Internet of Things (IoT) applications that use wireless ad hoc networks is expected to increase. To realize a highly reliable wireless ad hoc network, it is essential to introduce a method for cancelling the interference from other users. This research adopts a method based on code division multiple access (CDMA). However, a CDMA-based method has difficulty with deteriorating performance due to the near-far problem and the increase in the amount of interference as the number of users increases. Another problem is that the spreading sequence of each user is unknown in a wireless ad hoc network. The EOMF effectively removes interference while solving the above problems by combining an OMF and an adaptive array antenna. In this research, an EOMF structure with multiuser detection and lower computational complexity than the conventional EOMF is proposed. By the derived formulas and numerical examples, the proposed structure reduces the computational complexity by approximately 75% compared to the conventional EOMF and obtains sufficient bit error ratio (BER) performance.
... In addition, another problem is that in a MANET, the spreading sequence of each user is unknown [12][13][14]. The orthogonal matched filter (OMF) has been applied to address this problem [16][17][18][19]. The OMF cancels interference by generating and subtracting a replica of the interference signal that is contained in the received signal [16][17][18][19]. ...
... The orthogonal matched filter (OMF) has been applied to address this problem [16][17][18][19]. The OMF cancels interference by generating and subtracting a replica of the interference signal that is contained in the received signal [16][17][18][19]. This scheme is suitable for MANETs because it can generate a replica of the interference signal that is contained in the received signal even though the spreading sequence that is used by the interference node is unknown. ...
... The OMF consists of one matched filter (MF) with the same sequence as the desired node's spreading sequence and N-1 matched filters (which is called the matched filter group: MFG) with a sequence that is orthogonal to the desired node's spreading sequence [16][17][18][19][20]. N is the sequence length of the spreading sequence. ...
This study provides a mathematical model and theoretical analysis of an interference cancellation system combining an orthogonal matched filter (OMF) and adaptive array antenna that is called the extended OMF (EOMF). In recent years, an increase in the number of applications of mobile ad hoc networks (MANETs) is expected. To realize a highly reliable MANET, it is essential to introduce a method for cancelling the interference from other nodes. This research focuses on a scheme based on Code Division Multiple Access (CDMA) that enables simultaneous multiple access and low latency communication. However, there are problems with deteriorating performance due to the near–far problem and the increase in the amount of interference as the number of users increases. Additionally, another problem is that the spreading sequence of each user is unknown in a MANET. The OMF is expected to be a solution to these problems. The OMF performs interference cancellation by generating and subtracting a replica of the interference signal that is contained in the received signal. However, the OMF may generate an incorrect replica in the near–far problem. The EOMF compensates for the OMF’s weakness by combining the OMF with an adaptive array antenna. In this research, optimal parameters are derived from mathematical modelling and theoretical analysis of the EOMF. Specifically, the optimal weight vector and the minimum mean squared error that allow the adaptive algorithm to converge are derived and obtained from the numerical results.
... Fractal array antennas (FAAs) are large antenna apertures having multiband and multi-beam behaviors. These antennas and array antennas find applications in both the civilian and military fields owing to their optimum properties such as high gain, multi-beam, less side-lobe levels [1,2], and ultrawideband behavior [3]. Thinned arrays are becoming popular because of their improved array factor properties with some percentage of removed elements and this can lead to the ease of practical implementation of the proposed system. ...
Fractal arrays are repetitive-geometry-based smart arrays having impressive array factor properties. However, the performance of these arrays degrades owing to their large number of antenna elements at higher expansion levels. This research work presents the thinning of Sierpinski fractal arrays while keeping an applicable balance between all array factor properties by using two types of bounded binary-fractal-tapering techniques known as Sierpinski and Haferman carpet anti-diagonal tapering techniques. Approximately 22% to 50% of antenna elements are thinned in each successive iteration of the Sierpinski fractal array with the proposed tapering techniques.
