Huawei H35-580_V2.0 Exam Dumps - Actual Questions Answers

To find the number of RBs in a 5G cell, we need to know the bandwidth and the subcarrier spacing of the cell. The bandwidth is the total frequency range allocated for the cell, while the subcarrier spacing is the frequency separation between adjacent subcarriers in the cell. A RB is a group of 12 consecutive subcarriers in the frequency domain 12. Therefore, the number of RBs in a 5G cell can be calculated by dividing the bandwidth by the product of the subcarrier spacing and 12.

Given that the bandwidth is 100 MHz and the subcarrier spacing is 60 kHz, we can use the following formula to find the number of RBs:

Number of RBs = Bandwidth / (Subcarrier spacing * 12) Number of RBs = 100 MHz / (60 kHz * 12) Number of RBs = 100000 kHz / 720 kHz Number of RBs = 138.888…

However, since the number of RBs must be an integer, we need to round it down to the nearest multiple of 3 3. This is because the NR standard defines different frequency ranges for different subcarrier spacings, and each frequency range has a minimum and maximum number of RBs that are multiples of 3 4. For example, for subcarrier spacing of 60 kHz, the frequency range is from 24250.08 MHz to 52600.08 MHz, and the minimum and maximum number of RBs are 66 and 273, respectively.

Therefore, the closest multiple of 3 to 138.888… is 135. However, this number is not valid because it is lower than the minimum number of RBs for subcarrier spacing of 60 kHz. The next valid multiple of 3 is 273, which is also the maximum number of RBs for subcarrier spacing of 60 kHz. Therefore, the correct answer is C. 273.

According to the 5G NR Physical Layer Specifications, demodulation reference signals (DMRSs) are required for the following channels/signals in the downlink and uplink:

• Downlink Physical Broadcast Channel (DPBCH)
• Downlink Physical Downlink Control Channel (DPDCCH)
• Downlink Physical Shared Channel (DPOSCH)
• Uplink Physical Random Access Channel (PRACH)
• Uplink Physical Uplink Control Channel (PUCCH)
• Uplink Physical Uplink Shared Channel (PUSCH)

In order to achieve ideal coverage, there should be a clearance zone around an antenna of at least d, where d is the Fraunhofer or Rayleigh distance at which the near/far-field transition zone exists 17. This distance depends on the largest dimension of the antenna, D, and the operating wavelength, \uF06C. Ideally, D should be at least a half of a wavelength, which gives a minimum clearance zone of a half-wavelength. For example, at 2.4 GHz, the wavelength is about 0.125 m, so the minimum clearance zone is about 0.0625 m. However, in practical situations, this clearance zone is often compromised and the effects must be determined through simulation or empirical measurement 18. A general guideline is to have a clearance zone of 5-10 m around an antenna to avoid significant degradation of performance 19. Therefore, the best answer is C.