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A BTS has a coverage limitation by the ouput power. RRU system can enlarge the coverage with a low cost. RRU system is composed of Donor unit and Remote unit. Donor unit is placed with channel card pool and control several Remote unit.
Donor unit and Remote unit is connected by optic cable and the maximum distance is 20Km. A high technology which is called CFR(Crest Factor Reduction) and DPD(Digital Pre-distortion) is applied to Remote unit.
This new technology enables the high efficiency and high power output.
Donor unit and Remote unit is connected by optic cable and the maximum distance is 20Km. A high technology which is called CFR(Crest Factor Reduction) and DPD(Digital Pre-distortion) is applied to Remote unit.
This new technology enables the high efficiency and high power output.
[Figure 1. RRU Cell Deployment]
[Figure 2. The Application of RRU]
Figure 2 shows the application example. A type 2 Remote unit is placed in same place with Donor unit and connected by STP cable for low cost implementation
A. DPD (Digital Pre-distortion)
B. CFR (Crest Factor Reduction)
C. Digital BDT (BTS Diagnostic and Test)
DPD
A high power amplifier has a inherent non-linear component. DPD is applied to overcome this non-linearity. A linear high power amplifier implementation is possible through this DPS technology ACE Dixxio DPD technology can support upto 20MHz bandwidth.
B. CFR (Crest Factor Reduction)
C. Digital BDT (BTS Diagnostic and Test)
DPD
A high power amplifier has a inherent non-linear component. DPD is applied to overcome this non-linearity. A linear high power amplifier implementation is possible through this DPS technology ACE Dixxio DPD technology can support upto 20MHz bandwidth.
[Figure 3. A screen capture of spectrum analyzer.]
CFR
The crest factor which is happened during the signal modulation process. It’s act as a bad component for the power amplifier because power amplifier should have a operating 1dB point margin for it. So, if the crest factor could be small without any performance degradation
The crest factor which is happened during the signal modulation process. It’s act as a bad component for the power amplifier because power amplifier should have a operating 1dB point margin for it. So, if the crest factor could be small without any performance degradation
[Figure 4. The CFR Technology Process]
[Figure 5. The Effect of Crest Factor Reduction]
[Figure 6. The CFR Reduction in Real Test]
Digital BDT
Digital BDT can control the Remote unit in a Donor side. It’s important function for the easy maintenance and control
Digital BDT can control the Remote unit in a Donor side. It’s important function for the easy maintenance and control
| ITEM | DESCRIPTION | NOTE |
| VSWR | TX. Antenna VSWR | |
| Spectrum | Display of Tx. Signal Spectrum | |
| Waveform | Display of Tx. Signal Waveform | |
| Code Domain | Display of Tx. Signal Code Domain | |
| PD | Display of Power Amp. Tx. Power | |
| VSWR | RX. Antenna VSWR | |
| RSSI | Receiver Signal Strength Indicator | |
| OUNS | Other User Noise System | |
| Spectrum | Display of Rx. Signal Spectrum |
