| 摘要 |
PROBLEM TO BE SOLVED: To reduce delay by filtering processing at an unnecessary signal component removing unit in a cellular system in which base station functions are separated into a baseband unit (BBU) and a remote radio unit (RRU) and physically away.SOLUTION: At a remote radio unit (RRU) side, an unnecessary signal component removing unit increases a filtering transition region, reduces the number of required taps, and shortens delay time when performing filtering processing on the time domain. As a result, the unnecessary signal component removing unit may partly suppress a desired signal component, and distort a radio signal. Therefore, in a downlink from a baseband unit (BBU) to the RRU, an amplitude adjusting unit increases in advance the desired signal component that may be partly suppressed by the unnecessary signal component removing unit when the amplitude adjusting unit performs amplitude adjusting processing on the frequency domain. On the other hand, in an uplink from the RRU to the BBU, the amplitude adjusting unit increases after the fact the desired signal component that was partly suppressed by the unnecessary signal component removing unit when the amplitude adjusting unit performs amplitude adjusting processing on the frequency domain. |
