From Obw
Posted in Uncategorized on 04/15/2005 09:53 pm by admin
From Obw
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US $39.95
Spectrum Analyzer In The Mobile Wireless Communications Test Applications
2009, as the nation operating license issuing 3G licenses, China's entry into the 3G era. Faced with new opportunities and challenges, both Communicate Operators or handset manufacturers have begun a new round of competition. Communicate the existence of mobile phone frequency band during control, communication quality control testing and signal size of the problem. RF engineers are referred to as "RF Multimeter "The spectrum analyzer in spectrum analysis, the absolute advantage can help to solve these problems. This article will mobile wireless communication issues encountered in the corresponding solutions.
Question one: all communications operators to control their own communications band
ITU spectrum of communications for the strict definition, industrial and scientific communications, fixed and mobile services, satellite communications and other means of communication must be carried out within their respective bands, even in the same range of frequency of various business Communication also has a strict definition. If the communication frequency bandwidth is beyond the scope of their distribution will not only interfere with other communications and energy will affect their communication. Therefore, the need for communications bandwidth and signal energy concentration tested.
Problem II: the need to ensure the quality of communication signals
In mobile wireless communications when the channels have a variety of noise mixed in there, and noise caused deterioration of the quality of communication signals, so the need for communication channel signal to noise ratio measurement.
Question 3: In the mobile wireless communication systems will exist in the respiratory effect and distance effect
In wireless communication systems, when a district of the interference signal is very strong, effective and efficient base station coverage area will be reduced; When a cell of the interference signal is weak, the real base station will be larger effective coverage This is the breathing effect. In short, the coverage radius of respiratory effect showed the number of users increases with the contraction. As the mobile phone users within a cell is randomly distributed, and is constantly changing, sometimes in the same cell phone users may be the edge, and sometimes close to the base station. If the phone's transmitting power according to the design maximum communication distance, then when the phone close to the base station, the power must be a surplus, and the formation of harmful electromagnetic radiation, which is near-far effect. Solution to this problem is based on the different communication distance, real-time mobile phone transmit power adjustment, or power control. This requires the size of the communication signal in real time monitoring.
Spectrum analyzer can resolve these three issues, the following companies to launch DSA1030A RIGOL spectrum analyzer, for example, details on how to test. DSA1030A spectrum analyzer in the frequency range 9kHz ~ 3GHz, displayed average noise level DANL to-148dBm, typical phase noise value -88dBc/Hz @ (Offset 10kHz), the whole range of accuracy of less than 1.0dB, can help solve the mobile application problems. Meanwhile, DSA1030A spectrum analyzer also has a key measurement of rich features, you can deal with complex needs. The following to test a TD-SCDMA signal to illustrate the role of the spectrum analyzer.
For issues and problems of a second spectrum analyzer can be used DSA1030A ACP in adjacent channel power measurement and OBW measurement bandwidth to solve. Ling Dao power measurement can measure the main channel power, after the previous channel and a channel of power, and the main road and between the upper and lower adjacent channel signal to noise ratio measurement, the bottom left of Figure 1 for the measurements. Flexible according to specific needs of the user to set the main channel bandwidth, adjacent channel bandwidth and the main road and adjacent-channel spacing between the size of the bottom right of Figure 1 set the value for the measure. Ling Dao power measurement through the use of the function can be clearly measured the energy of communication channels and communications signal to noise ratio. Figure 1 can be drawn from the main road and the energy-10.69dBm largely concentrated in the 1.6MHz bandwidth, the line TD-SCDMA signal bandwidth of 1.6MHz each carrier's requirements. Adjacent channel suppression is-51.32dB and-51.66dB, meet the general needs.
Figure 1 ACP measurement using the signal energy and signal to noise ratio
OBW bandwidth function can detect whether they are concerned with some of the energy of a specific bandwidth. By setting the power ratio was 99%, measured within the signal bandwidth 1.396666MHz contains 99% of energy.
About the Author
I am China Toys Suppliers writer, reports some information about garmin street pilot c330 , magellan gps 2000.
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