tailieunhanh - WIMAX, New Developments 2011 Part 11

Tham khảo tài liệu 'wimax, new developments 2011 part 11', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | WiMax Interference and Coexistence Studies with Other Radio Systems 263 Figure 6 shows the probability of UWB device is located inside the interference zone based upon the victim receiver and interferer parameters. When we take the interference zone radius from the Table 3 and set it to the Figure 6 it will give us the probability of interference power arrived to the victim receiver. For example at UWB transmit power of -70 dBm MHz noise figure of 6 dB and noise raise limit of 3 dB interference zone radius of m is determined. That means the interference impact on victim is negligible when the interferer is located outside of the zone. The probability of UWB devices being located inside this are is . If the receiver noise raise is 1 dB then the probability reaches to 11 . However for transmit power of -80 dBm MHz the examined probability is negligible for any distance even at the receiver limited noise raise of 1 dB. Table 4 represents this probability for various combinations of receiver and transmitter parameters. Probability of Interference for Different UWB Power Emission Levels We have performed a system level simulation using SEAMCAT Spectrum Engineering Advance Monte Carlo Analysis Tool SEMCAT software tool in order to compute more precise result of probability of interference from UWB transmitter to WiMax victim client receiver. It is a tool developed by the group of CEPT administrations ETSI members and international scientific bodies to study the coexistence problem between radio systems. It is an implementation of Monte Carlo methodology whose main principle is taking samples of random variables from their probability density functions defined by user and then using those samples to calculate the probability of interference. The parameters presented in the Table 2 are used to perform the simulation. A uniform polar distribution is carried out to distribute the UWB transmitter over the area between two circles with radius of m and 2 m .