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Showing papers on "GSM frequency bands published in 2005"


Patent
Juha Ellä1, Tero Tapio Ranta1
31 Mar 2005
TL;DR: The combination of filters and switches is used to solve the nonlinearity problems in GSM/WCDMA transceiver front-end wherein one common antenna is used for both the GSM mode and the W-CDMA mode as mentioned in this paper.
Abstract: The combination of filters and switches is used to solve the non-linearity problems in GSM/W-CDMA transceiver front-end wherein one common antenna is used for both the GSM mode and the W-CDMA mode In particular, separate Rx/Tx paths and switches in the Rx paths are used to provide cross-band isolation between bands All of the switches in the transceiver are disposed after the filters in that no switches are disposed between the filters and the antenna Furthermore, bandpass filters are matched to one common node even if they are only disconnected at the output as long as the impedance at the output can be controlled

55 citations


Journal Article
TL;DR: In this article, four different planar multi-band antennas are designed, modeled, fabricated, and measu- red. Parameters of the antennas are in detail compared to demonstrate advantages and disadvantages of different so- lutions.
Abstract: In the paper, four different planar multi-band antennas are designed, modeled, fabricated, and measu- red. Parameters of the antennas are in detail compared to demonstrate advantages and disadvantages of different so- lutions. Discussions are supported by results of the modal and full-wave analyses of antennas. The classical patch antenna is a basic building block of compared antennas. The multi-band behavior is achieved by etching perturbation slots to the patch, which influence resonant current distributions. The antennas are designed for GSM bands (900 MHz, 1 800 MHz), and for the Bluetooth band (2 400 MHz).

18 citations


Patent
Shin Young Wook1
16 Nov 2005
TL;DR: In this paper, an apparatus and method for switching a mode in a dual-mode terminal are provided, if the current operation mode is a GSM mode, a CDMA mode key is displayed upon booting of the dualmode terminal.
Abstract: An apparatus and method for switching a mode in a dual-mode terminal are provided. If the current operation mode is a GSM mode, a CDMA mode key is displayed upon booting of the dual-mode terminal. Upon selection of the CDMA mode key, the operation mode is switched to the CDMA mode. If the current operation mode is the CDMA mode, a GSM mode key is displayed upon booting. Upon selection of the GSM mode key, the operation mode is switched to the GSM mode.

11 citations


Journal ArticleDOI
TL;DR: In this paper, the potential for interference to consumer electronics from radio frequency (RF) fields radiated by general packet radio service (GPRS) 900/1800-MHz and wideband code division multiple access (WCDMA) 1900-MHz handsets was assessed.
Abstract: This study assessed the potential for interference to consumer electronics from radio frequency (RF) fields radiated by general packet radio service (GPRS) 900/1800-MHz and wideband code division multiple access (WCDMA) 1900-MHz handsets. The study was enhanced by additional testing with fields that were characteristic of radio transmissions from GSM 900/1800-MHz handsets and 900/1800-MHz fields that comply with the requirements of the international immunity standard to RF fields, IEC 61000-4-3. Four examples of consumer electronics were tested-a television, radio, CD player, and telephone. Generally, each device exhibited some form of interference at most of the test field levels (1, 3, 10, and 30 V/m). GPRS/GSM 1800-MHz and WCDMA signals never caused interference to any device at 1 V/m. The IEC 61000-4-3-specified test signal consistently produced more audio/visual interference than GPRS- or GSM-type signals at the same test frequency and carrier field strength level. Audio/visual interference produced by WCDMA signals was generally lower than that produced by GPRS. These results, combined with the inherently lower maximum output power of WCDMA, indicate that WCDMA will usually pose a lower risk of interference compared with GPRS for similar separation distances between handsets and common items of consumer electronics.

6 citations


Journal ArticleDOI
TL;DR: This paper presents the practical performance evaluation of a digital cellular system based on the GSM 900 standard and using radiated mode leaky coaxial cables implemented in an underground mass rapid transit environment and shows that the system performance is generally good; however, the poor system performance often occurs at the terminals of the leaking coaxial cable.
Abstract: Leaky coaxial cables have found applications in the creation of network infrastructures for mobile and personal communication services in underground and enclosed spaces. A digital cellular system based on the GSM 900 standard and using radiated mode leaky coaxial cables has been implemented in an underground mass rapid transit environment. This paper presents the practical performance evaluation of the system. First, we start with a brief introduction of a radiated mode leaky coaxial cable and the digital cellular system GSM 900, and then we move into a full description of the measurement campaign; next we focus on an analysis of the measured performance data about received signal level, received signal quality, speech quality index and grade of service. The results show that the system performance is generally good; however, the poor system performance often occurs at the terminals of the leaky coaxial cable. In addition, it is found that the system performance is highly correlated with the density of train passenger. The higher train passenger density degrades the system performance. Copyright © 2004 John Wiley & Sons, Ltd.

6 citations


Patent
13 Apr 2005
TL;DR: In this paper, a mobile phone which is suitable for a GSM or CDMA system mode is designed with a subsidiary communication module interface of the CDMA or GSM mode and is attached with an expandable GSM module.
Abstract: The utility model discloses a mobile communication equipment which can be suitable for honeycomb frequency band aspect. The utility model is mainly used for building the wireless communication of an IS95GSM network or a CDMA network. A mobile phone which is suitable for a GSM or CDMA system mode is designed with a subsidiary communication module interface of the CDMA or GSM mode and is attached with a subsidiary communication module of the CDMA or GSM mode. A). The mobile phone with the CDMA mode is attached with an expandable interface of the subsidiary communication module of the GSM mode, and the mobile phone with the CDMA mode is provided with an expandable GSM mode. B). The mobile phone with the GSM mode is attached with an expandable interface of the subsidiary communication module of the CDMA mode, and the mobile phone with the GSM mode is provided with an expandable CDMA mode. C). The CDMA mobile phone with the basic mode is attached with the subsidiary communication module of the GSM, and the CDMA mobile phone with the basic mode becomes double-mode mobile phone which can select CDMA and GSM. D). The GSM mobile phone with the basic mode is attached with the subsidiary communication module of the CDMA, and the GSM mobile phone with the basic mode becomes double-mode mobile phone which can select GSM and CDMA. The utility model really realizes global communication of using the same mobile phone.

4 citations


Journal Article
TL;DR: In this paper, a dual-band planar inverted-F antenna (PIFA) with a U-shaped slot was proposed for GSM 900 MHz/DCS 1800 MHz system.
Abstract: This paper describes a novel dual-band planar inverted-F antenna (PIFA) loaded with a U-shaped slot The proposed PIFA uses a single coaxial feed and the end of the radiating patch is folded up for the miniaturization The purpose of this paper is to achieve a compact dual-band antenna for GSM 900 MHz/DCS 1800 MHz system Simulated results are computed by the software Ansoft HFSS80 (High Frequency Structure Simulator)

3 citations


Proceedings ArticleDOI
03 Jul 2005
TL;DR: In this article, the authors presented the optimized design of a dual-band GSM microstrip monopole antenna, which is impedance matched extremely well in the GSM frequency bands of 890-960 MHz and 1850-1990 MHz and the return loss is less that -20 dB at all frequencies in the bands of interest.
Abstract: By combining GA with FDTD, integrated multiband antenna designs can be generated at arbitrary frequencies of interest. These antennas designs can use an arbitrary shape. This paper presents the optimized design of a dual band GSM microstrip monopole antenna. It is impedance matched extremely well in the GSM frequency bands of 890-960 MHz and 1850-1990 MHz and the return loss is less that -20 dB at all frequencies in the bands of interest. The antenna shows an extremely flat radiation pattern, with small dimensions which show the ability of the GA to utilize available space to create a compact and relatively broadband antenna.

2 citations


Journal Article
TL;DR: The gathering design technique between the terminal to collect the data and decision support system to make use of GSM mode to proceed data correspond and designing and application through SMS technology in humidity monitor of cotton field are discussed.
Abstract: This paper gave a designing and application of the system through SMS technology in humidity monitor of cotton field, and discussed the gathering design technique between the terminal to collect the data and decision support system to make use of GSM mode to proceed data correspond.

1 citations


Proceedings ArticleDOI
25 Sep 2005
TL;DR: This article presents, based on an original model for Quality of Service evaluation, a real case study of different frequency assignment strategies: classical plan (Base-band Frequency Hopping) and several sizes of one-to-one pattern (Synthesized Frequencyhopping).
Abstract: The use of frequency hopping systems in GSM networks has altered the issue of quality evaluation because the traffic of the stations, their field strengths and assigned frequencies become highly linked. This article presents, based on an original model for Quality of Service evaluation, a real case study of different frequency assignment strategies: classical plan (Base-band Frequency Hopping) and several sizes of one-to-one pattern (Synthesized Frequency Hopping). The consistency of these strategies with changes of traffic loads over the day shows that some tradeoffs can be made between protecting the busiest hour and maximizing the quality over the day. Finally, some associated on-field results and concerns are discussed.

1 citations


01 Jan 2005
TL;DR: In this article, a highly linear sigma-delta modulator for dual-standard receivers is presented, which employs a 2 nd order single-bit SDS modulator with feedforward path for GSM mode and a 4 th order modified SDS with single bit in the first stage and 4-bit in the second stage for WCDMA mode.
Abstract: A highly linear sigma-delta modulator for dual- standard receivers is presented. The modulator makes use of low- distortion sigma-delta modulator architecture to attain high linearity over a wide bandwidth. The dual-band modulator employs a 2 nd order single-bit sigma-delta modulator with feedforward path for GSM mode and a 4 th order modified cascaded modulator with single-bit in the first stage and 4-bit in the second for WCDMA mode. The modulator is designed in TSMC 0.18um CMOS technology and operates at 1.8 supply voltage. It achieves in GSM/WCDMA mode a peak SNDR of 83/75dB, a 96/84dB SFDR and an IMD3 of -93/-82dB for an OSR of 160/16.