Krairiksh, Monai
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Krairiksh, Monai
Alternative Name
Krairiksh', Monai
Krairiksh, M.
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Email
monai.kr@kmitl.ac.th
12 results
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Item type:Publication, A switched-beam element phased array antenna for CMA initialization(2006-01-01); This paper proposes an initialization scheme for a Constant Modulus Algorithm (CMA). The technique can significantly improve convergence properties of CMA, which is employed for weight adjustment of an adaptive antenna system. The technique exploits a beam of a switched-beam element phased array antenna with the maximum received power to initial CMA. In addition, a main beam of the antenna can be switched into more directions by utilizing four one-bit phase shifters. Antenna patterns are shown and selected for CMA initialization. Simulation results are shown to evaluate SINR performance of the proposed technique. © 2006 EuMA. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Efficient parallel architecture for implementation of the CMA adaptive antenna(2013-07-01); This paper presents an efficient parallel architecture for implementation of a constant modulus algorithm (CMA) adaptive array antenna. By inserting delay units into the original CMA, a novel delayed CMA (DCMA) that can significantly reduce the associated critical path is derived. Consequently, a pipelining architecture that supports parallel processing is introduced for implementation of the DCMA. In addition to the pipelining technique, a power-of-two multiplier is proposed for the DCMA leading to the efficient FPGA implementation. The effects of delays and finite word-length on the convergence property of CMA are investigated via simulations. Moreover, the synthesized results demonstrate that FPGA implementation of the proposed architecture using power-of-two arithmetic achieves 26.9% resource reduction in comparison with that of fixed-point arithmetic and operating clock frequency higher than 65 MHz. The implemented FPGA was tested to confirm that the designed architecture operates well for CMA. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Wordlength effect on CMA adaptive antenna with digital beam synthesis initialization(2008-12-01); This paper investigates the wordlength effect on the CMA adaptive antenna with digital beam synthesis initialization. The antenna is a four-element circular array whose main beam can be switched into different directions by using digital beam synthesizer. A beam obtained from digital beam synthesis is exploited as an initial beam for CMA. A weight vector for generating initial beams of CMA is chosen by determining radiation patterns. The SINR of the digital beam synthesis-based CMA adaptive antenna with different wordlengths are shown. Moreover, the step-size constant of CMA is also investigated and properly chosen to avoid underflow and overflow phenomena. © 2008 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Adaptive array antenna using on-off and CMA algorithms for microwave RFID readers(2011-01-01); ; This paper proposes an adaptive antenna using a combination of on-off and CMA algorithms. With the proposed technique, the on-off algorithm is first employed to search for a desired signal direction in which maximum received power is achieved. Then, interference is suppressed by performing CMA. Simulations are conducted according to the potential application of the proposed adaptive antenna. The simulation results show the SINR improvement implying that the proposed adaptive antenna can be applied to microwave RFID systems in order to resolve reader collision. Furthermore, the proposed adaptive antenna is implemented and then experimented. The experimental results verify that the proposed adaptive antenna can reduce interference resulting in the collision problem. Copyright © 2011 The Institute of Electronics, Information and Communication Engineers. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Performance of switched-beam element phased array for handset adaptive antenna(2007-12-01); ; This paper evaluates the performance of a handset adaptive antenna using a constant modulus algorithm (CMA). The antenna is a switched-beam phased array antenna which can assist initialization of CMA. The method to improve convergence property of CMA exploits a beam with maximum received power from several switched-beams of the antenna as an initial beam. Simulation results in term of signal-to-interference plus noise ratio (SINR) are shown to validate that the proposed antenna has a good performance and is suitable for installation on a handset. © 2007 EuMA. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Adaptive array processing unit based on direct data domain least square approach using conjugate gradient method(2007-12-01); ; Sarkar, Tapan K.This paper presents the design of an adaptive array processing unit based on direct data domain least square approach using conjugate gradient method. The unit was applied for operation in the adaptive antenna scenario. The efficient architecture for FPGA implementation using fixed-point operation is present. The simulations are shown to evaluate the performance of the proposed adaptive processing unit. Moreover, simulation results obtained from the unit using fixed-point operations also show a good agreement with the unit using floating point operations. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Parallel multistage CM array with constrained initialization of digital beam synthesis(2008-12-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Beam-switching-assisted CMA initialization for handset adaptive antenna(2007-08-28); ; This paper presents two initialization schemes: phased array-assisted initialization and switched-beam element phased array-assisted initialization, for a constant modulus algorithm (CMA). Both techniques utilize a beam with maximum received power obtained by beam-switching of array antenna to initial CMA. The techniques can significantly improve convergence properties of CMA, which is employed for weight adjustment of an adaptive antenna system. The architecture of the proposed adaptive antenna system is illustrated to show the low-cost assistance for CMA initialization. Finally, simulation results are shown to evaluate SINR performance of the proposed techniques. ©2007 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Simple initialization scheme for CMA adaptive antenna by using digital beam synthesis(2008-10-06); This paper presents a simple technique of initialization for CMA adaptive antenna. The technique utilizes digital beam synthesis for a circular array antenna to synthesize the beams in digital domain. The synthesized beam can be switched into different directions by choosing proper weight vectors. The weight vectors are calculated through a phased array principle. The beams obtained from the synthesis are employed to initial CMA in order to improve its convergence property. The technique makes the compact adaptive antenna using CMA possible. Simulation results show that the proposed technique can significantly improve the convergence property of CMA. ©2008 IEEE. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Wordlength effect on CMA adaptive phased array antenna using fixed-point arithmetic(2005-12-01); This paper investigates a wordlength effect on an adaptive phased array antenna using the Constant Modulus Algorithm (CMA). The antenna is a flat four-beam compact phased array whose main beam can be switched into four directions by using four one-bit phase shifters. A beam with maximum received power is exploited as an initial beam for CMA. The wordlength investigation will be shown in term of the signal constellations, SINR trajectories and antenna patterns. © 2005 IEEE.