A list may contain up to 2000 frequency level entries. Frequency hopping spread spectrum file exchange matlab. Frequency hopping in gsm networks o gsm networks use slow frequency hopping, a hop occurs before each time slot is transmitted every 4. Therefore, gsm frequency hopping belongs to slow frequency hopping. Frequency hopping parameters can be changed in any operating mode, but the test sets operation is not effected until it is set to a valid operating mode. Usually, power control and discontinuous transmission technologies are adopted to lower system interference. Slow frequency hopping is a quality and capacity enhancement feature for the gsm system. By transmitting the message energy over a bandwidth much wider than the minimum required, spread spectrum modulation techniques present two major advantages. Frequency hopping for gsm base station tests with signal.
Gsm radio interface uses slow frequency hopping sfh technology. The main technique for frequency hopping is that 1 carrier atleast uses more than one predefined frequecy to serve their purpose. The difference between slow frequency hopping and fast frequency hopping is that the frequency of latter changes faster than frequency modulation. Pdf slow frequency hopping solutions for gsm networks of. Frequency hopping in list mode for each frequency the associated level is also stored in the lists. However, in order to achieve a significant gain from frequency hopping, it has been shown that at. We modified airprobe to support hopping channels by taking iq data samples from files corresponding to each arfcn of interest. In gsm, the frequency remains the same during burst transmission. O in fh each call hops between a defined set of frequencies. In b aseband hopping, the transmitter will change its frequency on frame basis.
Frequency hopping spread spectrum fhss and direct sequence spread spectrum dsss. Pdf user description, frequency hopping kamillion iam. This enables incoming signals of different strength to be simulated for receiver testing. Pdf slow frequency hopping is a quality and capacity enhancement feature for the gsm system. 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. Frequency hopping free download as powerpoint presentation. When using close frequency reuse technique, system interference is the most important factor for frequency reuse ratio.
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