GSM frequency bands

About: GSM frequency bands is a research topic. Over the lifetime, 559 publications have been published within this topic receiving 5067 citations.

Multi-frequency plane printed antenna comprising protruded floor and applied to mobile terminal

Abstract: The invention discloses a multi-frequency plane printed antenna comprising a protruded floor and applied to a mobile terminal and belongs to the technical field of mobile terminal antennas The multi-frequency plane printed antenna is characterized in that two resonance structures, namely a simulation branch and a parasitism land branch are utilized to select and combine all resonance modes which are simulated so as to obtain broadband and multi-frequency characteristics A coaxial probe feeding manner is utilized to improve the reliability of test results, and impedance matching is performed by loading an adjusting piece In addition, with the protruded floor structure, under the condition that acceptable antenna performance is ensured, placing spaces are provided for electronic equipment such as a camera, a loudspeaker, a data interface, a power supply and an earphone interface, wherein the electronic equipment possibly needs to be placed The area of a clearance zone occupied by the multi-frequency plane printed antenna on a circuit board is only 15mm*283mm, a -6dB impedance bandwidth of the multi-frequency plane printed antenna can effectively cover work frequency bands of GSM 850, GSM 900, DCS, PCS, UMTS, LTE 2300, 24-GHz WLAN, LTE 2500 and the like

Hard switching method between TD-SCDMA (Time Division-Synchronization Code Division Multiple Access) and GSM (Global System for Mobile Communication) of multimode terminal comprehensive test instrument

Abstract: The invention relates to a hard switching method between TD-SCDMA (Time Division-Synchronization Code Division Multiple Access) and GSM (Global System for Mobile Communication) of a single-radio-frequency multimode terminal comprehensive test instrument, belonging to the technical field of mobile communication of TD-SCDMA and GSM and aiming at reducing the manufacturing cost of the multimode terminal comprehensive test instrument and improving the switching success rate. The method comprises the steps: a TD-SCDMA module of the multimode terminal comprehensive test instrument transmits hard switching signaling from UMTS (Universal Mobile Telecommunication System) to a GSM switching request; after determining that the hard switching signaling is transmitted, the multimode terminal comprehensive test instrument controls a radio-frequency module to change the frequency of a transmitter and a receiver; the multimode terminal comprehensive test instrument starts a GSM protocol module and enters a GSM mode; and a terminal receives a broadcast message from a GSM cell of the multimode terminal comprehensive test instrument and carries out signaling interaction with the multimode terminal comprehensive test instrument under the GSM mode to finish hard switching. In the method, due to adoption of the scheme that single-radio-frequency transmitting-receiving hardware structure realizes hard switching from the TD-SCDMA to the GSM, so that the production cost of the terminal comprehensive test instrument can be greatly reduced, the hardware structure can be simplified, and the hard switching method has the advantage of being high in switching success rate.

Planar Inverted-L Antenna for Octa-Band Operations of Smart Handsets

Abstract: This paper applies inverted-L antenna (ILA) to design a smart handset antenna in accordance with octa-band operations, as GSM 850 (824–894 MHz), GSM 900 (880–960 MHz), GSM 1800/1900, DCS 1800 (1710–1880 MHz), PCS 1900 (1850–1990 MHz), UMTS (1920–2170 MHz), IEEE 802.11b WLAN (2400–2484 MHz) and LTE (1700 MHz/2300 MHz/2600 MHz) band operations for S 11 ≦ −10 dB. The entire antenna is 70 mm × 24 mm with one-quarter wavelength design of hub. With the inter-coupling between dual branch circuit radiation and multiple branch circuit radiation, the wideband for GSM 1800/1900, DCS, PCS, UMTS, IEEE 802.11b WLAN and LTE 1700/2300/2600 is generated. When integrating with mobiles, the designed ground plane area is also taken into consideration. In this case, the ground plane area can be increased in accordance to the system motherboard. The enlarged antenna size therefore becomes 9 mm × 42 mm that the ground plane area does not affect the bandwidth and can enhance the impedance matching. Consequently, the mobile anten...

Frequency generating system for a mobile radio dual-band transceiver

Abstract: In a frequency generating system, a triple/single local-oscillator concept for receiving and transmitting in the lower frequency band, transmitting in the upper frequency band, and receiving in the upper frequency band is used for a dual-band transceiver so that a single band-switched VCO can be used as local oscillator for setting the frequency in all four possible operating cases. The system can be used, for example, in highly integrated dual-band mobile parts for GSM 900/1800 mobile radio.

Performance Comparison of Markov Chain and LSTM Models for Spectrum Prediction in GSM Bands

Abstract: A critical component of Cognitive Radio (CR) is an ability to predict availability of unused RF slots at a given time and location. Secondary users can use such unused slots without any licensing requirements as long as they retreat when the primary user wishes to occupy the band. With increasing demand on data bandwidth, frequencies in basic GSM bands often go under-utilized, and hence are excellent candidates for CR. RF channel utilization is largely random and hence difficult to predict. Use of machine learning techniques could alleviate some of the uncertainty in prediction. In this paper, we compare the performance of a Markov chain based model with a machine learning LSTM model for use in CR, in terms of accuracy. We have analyzed clusters of five channel-pairs for a given time period, considering the frequency planning guidelines of GSM.