Simulasi Handover Pada ASN-GW (Access Service Network-Gateway) WiMAX (Worldwide Interoperability Microwave Access)

WiMAX dengan standar IEEE 802.16e merupakan suatu standar untuk sistem mobile WiMAX. Dalam sistem mobile ini mengenal adanya sistem handover. Simulasi pada penelitian ini terdapat 2 skenario, yang sama-sama menggunakan ASN-GW. Simulasi terdiri dari intra ASN-GW dan inter ASN-GW. Hasil dari simulasi yang telah dilakukan pada intra ASN-GW menunjukkan grafik throughput yang memperlihatkan terjadinya handover dari masing-masing nodal yang terlibat.Kata kunci: mobile, handover, VoIP, intra ASN-GW, inter ASN-GW, throughput.

Performance Analysis of WOFDM-WiMAX Integrating Diverse Wavelets for 5G Applications

In the 5th generation (5G) and 6th generation (6G) of wireless mobile telecommunication networks, the requests for an elevated data rate with access to stationary as well as portable customers are going to be overwhelming. Mobile worldwide interoperability for microwave access (WiMAX) comes out as a favourable alternative that is intelligibly developed and more matured than wireless fidelity (Wi-Fi). Mobile WiMAX makes use of the orthogonal frequency division multiple access (OFDMA) technology for its two-way communication to enhance the system performance in fading environments making it more suitable for 5G applications. The diverse OFDM forms deliberated here are the fast Fourier transform- (FFT-) based WiMAX and discrete wavelet transform- (DWT-) based WiMAX. The suggested study exhibits the bit error rate (BER) and peak to average power ratio (PAPR) reduction by integrating different wavelet families, i.e., Haar, symlet, coiflet, and reverse biorthogonal over Rayleigh fading channel. The simulation results obtained by MATLAB depicts an improvement in PAPR reduction, and signal to noise ratio (SNR) requirement is also reduced by 6-12 dB by using DWT-incorporated WiMAX at a BER of 10-4.

Shortened LDPC codes accelerate OSD decoding performance

Medium-length LDPC codes are in demand in certain areas such as mobile environment (Wi-Fi and Mobile WiMAX) and in telecommand links from the ground to space because of their lower latency properties. However, because of the length of these codes is rather short, decoding error rates are worse than those of long-length codes. In this paper, we show that the combination of shortened LDPC codes, whose shortened positions are properly selected, and ordered statistic decoding (OSD) significantly improves the decoding error. For the best choice of shortening positions, we used the integer programming approach. In particular, we utilized Feldman–Wainwright–Karger code polytope for this purpose. Some studies have independently reported the efficiency of shortened LDPC codes and OSD methods. This paper emphasizes that their combination results in multiplicative effectiveness.

Analysis and design of inclined fractal defected ground-based circularly polarized antenna for CA-band applications

Design of single-feed circularly polarized (CP) microstrip antenna is proposed in this article. The design employs the concept of E-shape patch with inclined fractal defected ground structure (IFDGS), which can improve the impedance bandwidth, gain, and axial ratio (AR) bandwidth. The excellent enhanced impedance bandwidth, axial ratio bandwidth, and gain are achieved by an inclined E-shaped fractal etched on the ground plane. The parameter studies of the E-shaped IFDGS are given to illustrate the way to obtain CP radiation. The third iterative IFDGS is fabricated on easily available FR4 substrate with a size of 0.494 λ0 × 0.494 λ0 × 0.019 λ0 (λ0 is the wavelength in free space at 3.624 GHz). The measured results verify the simulated results and show good agreement. The proposed antenna shows an impedance bandwidth of 12.7% at a centre frequency of 3.47 GHz and 3-dB AR bandwidth for this band is 2.39% at a centre frequency of 3.626 GHz. The measured peak gain for the proposed antenna is found as 8.1 dBi. The proposed antenna can be suitable for mobile WIMAX operation (IEEE 802.16e-2005 standard), wireless communication in CA-band and FCC.