Fcc id application submitted by itron for cellular pcs gsm gprs power meter with frequency hopping transmitter for fcc id qhcgprscol50. Performance improvement in gsm networks due to slow frequency. Us8125388b2 method for calibrating an aoa location system. Frequency hopping by switching the synthesizer will not work, as the synth usually is too slow within the normal sdr radios. Softwarebased implementation of a frequency hopping twoway. Current implementations of fh are based on random or cyclic hopping patterns. Accessories supplied power cable, operating manual.
This leads to an improvement in performance of system and reduce the interference allowing. Pdf slow frequency hopping solutions for gsm networks of. Audience this document is intended for software developers and integrators using telit radio modules with frequency hopping star network protocol stack. Frequency hopping is one of the many techniques that are being considered to improve the spectral efficiency of gsm cellular networks. Frequency hopping spread spectrum fhss is a method of transmitting radio signals by jumping a carrier among many frequency channels, using a pseudorandom sequence known to both transmitter and receiver. This application note introduces the concepts of digital modulation used in many communications systems. Gummadi et al 8 propose a rapid proactive frequency hopping scheme to alleviate the impact of speci. Frequency hopping the frequency hopping algorithm allows the cognitive radio to avoid interference from malicious users. Gmsk gaussian msk gsm, dcs mini scanned pdf to htm ocr converter 3 2 1800, ct3, dect.
Chapter 2 introduces software radios, frequency hopping, and the 2. In gsm networks, frequency reuse has been the basic tool for. Interference analysis of a total frequency hopping gsm. Optimizing frequency hopping in gsm cellular phone. Introduction despite of limited spectrum, gsm cellular system has met tremendous growth over the past years and the demand for radio resources is continuously increasing. On total frequency hopping1 in 1 a new multiple access method, called total frequency hopping tfh, was presented for such a cts system.
Frequency hopping spread spectrum is defined in the 2. Digital modulation techniques, qpsk, fdma, tdma, pcm, frequency hopping. Baseband frequency hopping vs synthesized frequency hopping. Frequency planning strategies for frequency hopping gsm. For example, gsm standard uses fhss method to transmit radio signal among two or more channels depending on the. The slow frequency hopping sfh feature allows a mobile station in a gsm network to change its operation frequency from a time slot to another resulting in 217 hops per second. While a frequency assignment for slow frequency hopping networks is defined by the information, which trx should hop over which frequencies.
The gsm system has two type of frequency carriers, namely the frequencies that carry the broadcast control channels bcch and the frequencies carrying only. Softwarebased implementation of a frequency hopping. This technique can be applied on all traffic and signaling channels, except for the broadcast common control channel bcch, which must transmit on a fixed. In frequency hopping, the carrier frequency is controlled by a sequence and hops with time. Frequency hopping refers to the regular hopping of carrier frequency within certain range. For a specific user, a new frequency is used from one time slot to the next. The frequency of the carrier is periodically modified hopped following a specific sequence of frequencies. F r e q u e n c y h o p p i n g fo r s dr b a s e d g s m mo.
This paper investigates the performance of gsm systems employing slow frequency hopping when a limited number of hopping channels are used. So hopping only could be done by sampling the whole bandwidth of the intended hopping sequence, what can be quite a chunk of spectrum. Bts type select the type of bts base transceiver station to be tested normal, micro, or pico. Abstract slow frequency hopping is a quality and capacity enhancement feature for the gsm system. Frequency hopping is an old technique introduced firstly in military transmission system to ensure the secrecy of communications and combat jamming. The functions include encodingdecoding, cipheringdeciphering, frequency hopping gsm, spreading and rake receiver wcdma, mac wimax, protocol frame processing, mimo etc.
Mobile allocation ma set of n radio frequency channels to be used in the hopping sequence hopping sequence generator number hsn mobile allocation index offset maio equivalent of channel number in hopping. Frequency hopping basics bandwidth signal processing. Wo2009115563a1 frequency hopping pattern and arrangement. This technique can be applied on all traffic and signaling channels, except for the broadcast common control channel bcch, which must transmit on a fixed frequency in order to make possible correct rxlev measurements for the neighbor cell mobiles based on recommendation gsm 05. A method, an apparatus, and a computer program that includes forming frequency hopping position of the sounding reference signal is based on a hopping pattern. In a gsm gprsegprs network, frequency hopping is specified in individual cells based on the number of frequencies offered by a specific cell. Frequency hopping, global system for mobile communication gsm, grade of service gos, intelligent underlay overlay, cluster size, signal to interference ratio sir. Itron cellular pcs gsm gprs power meter with frequency. In fhss systems, the spreading code is this list of frequencies to be used for the carrier signal, a. A method for calibrating an antenna and signal processing system enabling angle of arrival aoa determination for a frequency hopping signal, in which a calibration coefficient is determined in response to one or more calibration signals injected into the system at one or more of the frequencies in the hopping sequence and proximate in time to reception of the communication signal. Frequency hopping is mechanism in which the system changes the frequency uplink and downlink during transmission at regular intervals.
Hoptrigger pin4 trigger1 instrument trigger earphone iqout iqin. Typical frequency hopping gain the following table shows the typical gain from frequency hopping in a gsm 900 network example of the signaltonoise ratio required to obtain 0. An analytical approach to enhance the capacity of gsm. Gsm slow frequency hopping is intended to reduce the adjacent cells interference by switching between a set of arfcns that are orthogonal to the set used by own cell. Also, the speed of gsm hopping is approximately 200 hops s. Gsm is the most widely accepted standard in telecommunications and it is implemented globally. Refer to the table in the previous section for gsm band data. This issue is addressed by an alternative operation mode proposed in ieee 802. The ultimate goal of a modulation technique is to transport the message signal. Digital modulation in communications systems pdf file.
Frequency hopping strategies can be divided into two main categories. It is a slow fh technique, which uses as much of the cellular gsm frequencies for fh in the cts systems as agreed with the gsm operators and the regulator, ideally the whole gsm frequency. Open base station architecture initiative wikipedia. Gsm physical layer modulation gsm uses gaussianfitered minimum shift keying. Slow frequency hopping vs fast frequency hopping gsm. Gsm is a circuitswitched system that divides each 200 khz channel into eight 25 khz timeslots. To gain the maximum benefit from frequency hopping it is necessary to modify the traditional design parameters to take into account the effect of frequency hopping. Performance enhancement of gsm cellular phone network using. Frequency hopping free download as powerpoint presentation.
Narrowband digital filtering with random frequency hopping. This means in gsm, rf carrier frequency is changed in each of the bursts transmission. The mode of frequency hopping can be decided by operators according to the equipments. Therefore, frequency hopping is a very important technology for reducing gsm system interference and improving frequency reuse ratio. Some of the specific gsm innovations described in this paper include. Pdf slow frequency hopping solutions for gsm networks of small. Different frequency for each gsm tdma frame 8 timeslots hopping sequence generation defined in 3gpp 05. Practical deployment of frequency hopping in gsm networks for. This document describes the features and the application of the star network embedded stack with frequency hopping available on telit modules le70915. Frequency hopping with signal generator sme 1gpan28e 2 07. This algorithm forces the device to change its transmission frequency after a specified time interval.
According to gsm standard recommendations, slow frequency hopping can be used in gsm communication system. It allows the rf channel used for signaling channel sdcch timeslot or traffic channel tch timeslots, to change frequency every tdma frame 4. This allows the transmission to occur over several frequencies which allows the data to tolerate a significant amount of inband interference providing that it affects only part of the spectrum. Frequency planning strategies for frequency hopping gsm ieee. Frequencyhopping spread spectrum is a method of transmitting radio signals by rapidly changing the carrier frequency among many distinct frequencies occupying a large spectral band. Gsm pesq is an addon tool for cmugo for automatic measurement of the pesq for gsm mobile phones according to recommendation itut p.
In fast frequency hopping type, one complete or fraction of data symbol is transmitted during the time between two frequency hops. The change of rf carrier frequency during the transmission of information is known as frequency hopping. Frequency hopping fh in gsm fh means that a trx shifts frequency at every new radio frame hopping is performed approximately 14. These channels are used for cs call and ps call in gsm. Frequency hopping for gsm base station tests with signal. The software implementation of frequency hopping demonstrated in this thesis is able to circumvent some of these difficulties. Pdf slow frequency hopping is a quality and capacity enhancement feature for the gsm system. Frequency hopping spread spectrum fhss does exactly what its name implies the carrier is automatically changed to hop from frequency to frequency. Optimizing frequency hopping in gsm cellular phone networks.
Shift keying gmsk, software defined radio, modulation scheme used in gsm. The hopping pattern of the sounding reference signal is configured to utilize a tree assignment for a frequency allocation of the sounding reference signal and to support at least one frequency band branch per layer. Consequently, gsm combined with frequency hopping, advanced radio planning, and new voice compression methods boost gsm capacity to equivalent to, or better than, cdma2000. Fhss is used to avoid interference, to prevent eavesdropping, and to enable codedivision multiple access communications. The limiting resource in this highly competitive market is the available frequency spectrum. However, in order to achieve a significant gain from frequency hopping, it has been shown that at. Softwarebased implementation of a frequency hopping two. A theoretical study of the performance improvement in. The behavior of the gsm rf parameters such as rxqual changes due to frequency hopping and the rf optimization of the cell parameters require careful attention.
The basic idea is, that the channel frequency, which is shared by each member of a piconet, is periodically changed. Us8125388b2 method for calibrating an aoa location. The hopping sequence may use up to 64 different frequencies, which is a small number compared to military fh systems designed for avoiding jamming. Dec 02, 2008 a frequency hopping algorithm is also assigned to the mobile and is used to inform the mobile of the pattern of the available frequencies it is to use. In a proactive frequency hopping scheme the pair of transceivers that form a link switch channels once every k seconds, irrespective of whether or not there is a jammer on the current channel.
The hopping techniques can be broadly classified into two main categories. Frequencyhopping spread spectrum fhss is a method of transmitting radio signals by rapidly changing the carrier frequency among many distinct frequencies occupying a large spectral band. However, in order to achieve a significant gain from. It allows the rf channel used for signaling channel sdcch timeslot or traffic channel tch timeslots, to change frequency. Following are the frequency hopping fh parameters used in gsm. Frequency assignments in slow frequencyhopping gsm networks. Download file pdf frequency hopping network planning guidefrequency hopping spread spectrum fhss is a method of transmitting radio signals by shifting carriers across numerous channels with pseudorandom sequence which is already known to the sender and receiver. The gsm uses interleaving, block and convolutional channel coding, frequency hopping and adaptive equalisation. The 3gpp releases its specification documents as a series of rele. Practical deployment of frequency hopping in gsm networks. Ma list are the rf frequencies which are given to one gsm sector. The frequency hopping function of the channel group in each cell can be enabled or disabled separately. Device select the device to test bts base transceiver station or ms mobile station. Frequency hopping gsm synthesizer free 30day trial.
Due to this, frequency hopping rate may exceed often compare to data bit rate in a binary sequence. Frequency hopping fh is a method that allows one to expand the available capacity of mobile networks or to improve the quality of service through interference averaging and frequency diversity. Performance enhancements in a frequency hopping gsm network. Performance enhancement of gsm cellular phone network.
Gsm is the name of a standardization group established in 1982 to create a common european mobile telephone standard. The gsm system has two type of frequency carriers, namely the frequencies that carry the broadcast control channels bcch and the frequencies carrying only traffic channel tch. F r e q u e n c y h o p p i n g fo r s dr b a s e d g s m. They are, base band hopping synthesised hopping as frequency hopping is a subject in it self, a separate document will be written concentrating on frequency hopping techniques in near future. The changes are controlled by a code known to both transmitter and receiver. The following referenced documents are not necessary for the application of the present document but they assist the user with regard to a particular subject area. Gsm global system for mobile communications is an open. Gsm 900 frequency band frequency hopping in gsm is intended for the reduction of fast fading caused by movement of subscribers. Openbts does not support fh at the moment, no matter what hardware you are using. Two basic frequency planning alternatives can be distinguished. Better resistance to interference introducing the frequency hopping efficient use of the power battery introducing the power control gsm. Algorithm and experimentation of frequency hopping, band. The advantages of fh are twofold frequency diversity interference diversity. Frequency hopping for gsm base station tests with signal generators sme.
Therefore, gsm frequency hopping belongs to slow frequency hopping. Tag performance parameters and test methods, version 1. In gsm, the frequency remains the same during burst transmission. Using frequency hopping in band limited one layer networks. A mobile allocation index offset maio refers a time delay separating traffic channels. The transport block interfaces to external network, and provides functions such as qos, security functions and synchronization. Document new network capacity and quality enhancement features for frequency hopping gsm. Gsm protocol does not specify which kind of frequency hopping is used in gsm bts.
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