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Journal : Journal of ICT Research and Applications

Design of RCPC Encoded V-BLAST MIMO System Lydia Sari; Gunawan Wibisono; Dadang Gunawan
Journal of ICT Research and Applications Vol. 3 No. 2 (2009)
Publisher : LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.ict.2009.3.2.1

Abstract

A Vertical Bell Laboratories Layered Space-Time Multiple-Input Multiple Output (V-BLAST MIMO) enhanced with Unequal Error Protection (UEP) to achieve highly reliable wireless communication is proposed. The UEP scheme is based on Channel State Information (CSI) available at the transmitter whose calculation utilizes Singular Value Decomposition (SVD) of the MIMO matrix channel. Using Rate-Compatible Punctured Convolutional (RCPC), a different code rate is given for each sub-stream of source information, according to its level of transmit power. To analyze the system performance, an analytical BER comprising the performance of V-BLAST MIMO BPSK-modulated signals and the performance of RCPC codes in Rayleigh fading environment is presented. Simulation results show that increasing the code rate can attain a bandwidth efficiency of 33.3% in expense Eb/No, but this penalty is not severe as the high code rate is used in sub-channels with high attenuation level. It is also shown that a system with 2 transmit and 4 receive antennas will have an improved performance within only 1 dB range compared to a system with 2 transmit and 2 receive antennas. The performance of the proposed system is mostly affected by the type of puncturing matrices chosen.
The Effectiveness of Chosen Partial Anthropometric Measurements in Individualizing Head-Related Transfer Functions on Median Plane Hugeng Hugeng; Wahidin Wahab; Dadang Gunawan
Journal of ICT Research and Applications Vol. 5 No. 1 (2011)
Publisher : LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.ict.2011.5.1.3

Abstract

Individualized  head-related  impulse  responses  (HRIRs)  to  perfectly suit  a  particular  listener  remains  an  open  problem  in  the  area  of  HRIRs modeling.   We  have  modeled  the  whole  range  of  magnitude  of  head-related transfer  functions  (HRTFs)  in  frequency  domain  via  principal  components analysis  (PCA),  where  37  persons  were  subjected  to  sound  sources  on  median plane.   We  found  that  a  linear  combination  of  only  10  orthonormal  basis functions was sufficient to satisfactorily model individual magnitude HRTFs. It was our goal to form multiple linear regressions (MLR) between weights of basis functions acquired from PCA and chosen partial anthropometric  measurements in  order  to  individualize  a  particular  listener's  H RTFs  with  his  or  her  own anthropometries. We proposed a novel individualization method based on MLR of  weights  of  basis  functions  by  employing  only  8  out  of  27  anthropometric measurements.  The  experiments'  results  showed  the  proposed  method,  with mean  error  of  11.21%,  outperformed  our  previous  works  on  individualizing minimum  phase  HRIRs  (mean  error  22.50%)  and  magnitude  HRTFs  on horizontal  plane  (mean  error  12.17%)  as  well  as  similar  researches.  The proposed  individualization  method  showed  that  the  individualized  magnitude HRTFs could be well estimated as the original ones with a slight error.  Thus  the eight  chosen  anthropometric  measurements  showed  their  effectiveness  in individualizing magnitude HRTFs particularly on median plane. 
Feasibility of LTE 700 MHz Digital Dividend for Broadband Development Acceleration in Rural Areas Denny Setiawan; Djamhari Sirat; Dadang Gunawan
Journal of ICT Research and Applications Vol. 6 No. 1 (2012)
Publisher : LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.ict.2012.6.1.2

Abstract

The need of broadband services to reduce digital divide in rural areas had increased in the recent years. The government of the Republic Indonesia shared similar intention and had set guidance of ICT development in its "economic master plan" and "medium term development plan". This paper addressed feasibility and suitability of its implementation in Indonesia, by conducting assessment of possible solutions. Using mixed method, the study was started with qualitative approach to identify possible options, conducted benchmarking and case study analysis to narrow down the options and finally conducted quantitative calculation for the two remaining options and measure performance of the solutions. The results of analysis concluded that early implementation of LTE in 700 MHz Digital Dividend would be feasible in certain geographical areas to fasten the broadband plan development in Indonesia.
Improved Performance of Mean Greedy Algorithm for Chunk Allocation in SC-FDMA Uplink Systems using Joint-User and Chunk-Based Allocation Arfianto Fahmi; Muhamad Asvial; Dadang Gunawan
Journal of ICT Research and Applications Vol. 7 No. 1 (2013)
Publisher : LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.ict.res.appl.2013.7.1.4

Abstract

In this paper, the problem of subcarrier allocation on chunk-by-chunk basis in SC-FDMA uplink systems is investigated. Improved mean enhanced greedy algorithms are proposed for performing joint-user and chunk-based allocation at each transmission time interval. Selection criteria based on spectral efficiency and fairness are also proposed to choose the final allocation at each transmission time interval. Simulation results show that when the number of users and the velocity of the users were varied, the improved algorithms that use selection criteria based on spectral efficiency and fairness could outperform the existing mean greedy algorithms that employ user-based allocation in terms of spectral efficiency and fairness. Moreover, the improved algorithms not only showed better performance but also had the same time complexity as the existing mean greedy algorithms.
Performance Analysis of Genetic Zone Routing Protocol Combined With Vertical Handover Algorithm for 3G-WiFi Offload Setiyo Budiyanto; Muhammad Asvial; Dadang Gunawan
Journal of ICT Research and Applications Vol. 8 No. 1 (2014)
Publisher : LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.ict.res.appl.2014.8.1.4

Abstract

In the deployment scenario of multiple base stations there is usually a deficiency in the routing protocols for load balancing in the wireless network. In this study, we propose a routing algorithm that can be implemented inMobile Adhoc Networks (MANETs) as well as third-generation (3G)"“Wireless Fidelity (WiFi) offload networks. We combined the Genetic Zone Routing Protocol (GZRP) with the Vertical Handover (VHO) algorithm in a 3G"“WiFioffload network with multiple base stations. Simulationresults show thatthe proposed algorithm yields improvement in the received signal strength(which is increased up to 25 dBm), user throughput (which is approximately 1 Mbps-2.5 Mbps), and data rate (which is increased up to 2.5 Mbps).
Electrical Capacitance Volume Tomography Static Imaging by Non-Optimized Compressive Sensing Framework Nur Afny Catur Andryani; Dodi Sudiana; Dadang Gunawan
Journal of ICT Research and Applications Vol. 10 No. 3 (2016)
Publisher : LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.ict.res.appl.2016.10.3.4

Abstract

Electrical capacitance volume tomography is a volumetric tomography technique that utilizes capacitance and fringing to capture behavior or perturbation in the sensing domain. One of the crucial issues in developing ECVT technology is the reconstruction algorithm. In practice, ILBP is most used due to its simplicity. However, it still presents elongation errors for certain dielectric contrasts. The high undersampling measurement of the ECVT imaging system, which is mathematically defined as an undetermined linear system, is one of the most challenging issues. Compressive sensing (CS) is a framework that enables the recovery of a sparse signal or a signal that can be represented as sparse in a certain domain, by having a lower dimension of measurement data compared to the Shanon-Nyquist theorem. Thus, mathematically, this framework is promising for solving an undetermined linear system such as the ECVT imaging system. This paper discusses the possibility of developing an ECVT imaging technique for static objects based on a CS framework. Based on the simulation results, Non-optimized CS does not completely succeed in providing better ECVT imaging quality. However, it does provide more localized imaging compared to ILBP. In addition, by having fewer requirements for the measurement data dimension, the CS framework is promising for reducing the number of required electrodes.