User's Manual

Open Information

DESCRIPTION 8 ( 19 )

ERA/RGN/PD Rikard Schönbeck 5/1551-HRB 105 102/1 Uen

ERA/RGG/TOC Jan Lundkvist 2002-05-28 B

Prepared (also subject responsible if other) No

Approved Checked Date Rev Reference

• Duplex filtering of the transmitter and receiver signal

• Low-noise amplification of the receiver signal

• Power measurement of transmitter signal

• Flexible frequency and signal splitting

The combiner and splitter unit performs frequency combination in the downlink,

signal splitting, and high power combination when two MCPA modules are

used. Frequency combination can be either two-way or four-way (when

three frequencies have to be combined, the fourth input is unused). When

using two MCPA modules for amplification, the combined signal is split, and

after amplification the signals are coherently combined again and sent to

one antenna.

RFIFB

The Radio Frequency Interface Board (RFIFB) connects the RF subrack to the

baseband subrack. The connection carries the downlink and uplink traffic, and

timing signals. The RFIFB also implements power clipping for downlink traffic.

TRXB

The Transceiver Board (TRXB) provides channel filtering, delay and gain

adjustment, A/D and D/A conversion, and RF modulation and demodulation.

A TRXB comprises two independent transceivers for two transmitter and

receiver signal pairs.

3.5 MCPA Subrack

The MCPA subrack contains the linear power amplifiers for the RF carriers. The

subrack contains positions for up to six MCPA modules. It is connected to the

RF subrack through front panel cabling.

MCPA

The MCPA is a 20 W RF power amplifier with a bandwidth of 20 MHz. Each

power amplifier can simultaneously amplify up to four RF carriers, by dividing

the power over the carriers. Two MCPAs can be combined to increase the

output power to 40 W by using the AIU in the RF subrack.

MCPA Hub

The MCPA Hub is the connection interface between the MCPA and the RFIF.

3.6 Internal Cables

This section gives a brief description of the internal RBS cables.

Inter-Subrack Link

The inter-subrack link is a common platform ATM interface cable for

inter-subrack communication. This interface cable is a high-speed point-to-point