Signal booster 5G interference troubleshooting

The inconsistent allocation of uplink and downlink time slots in adjacent stations of the same frequency will cause cells with more downlink time slots to interfere with cells with fewer uplink time slots.

The current mobile 5G trial has a time slot ratio of 4:1, 8:2, and 7:3, and there is time slot interference in mixed use. At present, Hubei uniformly adopts 8:2, which has been included in the start-up template.

5G and LTE TDD co-deployment also need to be synchronized, otherwise it will cause the downlink time slot of one system to fall into the uplink time slot of another system, causing interference.

At present, the frame bias of China Mobile's 2.6G 5G site is delayed by 3ms compared with LTE, which can ensure the alignment of time slots.

Since the Wuhan NSA anchor is in the F band, the LTE D band is moved forward, and the frame offset of 285768 (697us) is set to enable D/F frame structure alignment, and the NR frame offset needs to be set to 70728 (30720 * 3 - 0.697 * 30720 = 70728) to ensure LTE/NR frame structure alignment.

When a long-distance station signal is propagated and arrives at the interfered station, the attenuation is relatively small due to the good propagation environment. At the same time, due to the delay in the propagation process, the DwPTS of the interfering station is aligned with the UpPTS of the interfered station (in severe cases, it may even fall into the uplink subframe of the interfered station), causing the downlink signal of the interfering station to interfere with the uplink transmission of the interfered station.