User's Manual

CHAPTER 3. SPI-2213 Architecture

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Mobile WiMAX base station RAS board Assembly-Flexible (MRA-F)

The MRA-F provides a modem function of the SPI-2213 and interfacing with the RRH.

y Modem Function

The MRA-F is equipped with the modem supporting IEEE 802.16 Mobile WiMAX

standard physical layer (PHY) and the modem performs the OFDMA signal processing

function by the control of the MMA-G.

The MRA-F modulates the packet data received through the MMA-G, converts the

modulated signal into the ‘Digital I/Q and C & M’ format and transmits to the RRH.

In the contrary, the MRA-F demodulated the data received from the RRH after

performing the AGC function, converts the data into the format defined in the IEEE

802.16 Mobile WiMAX physical layer standard and then transmits the converted data

to the MMA-G via Ethernet.

By default, the MRA-F supports MIMO or 4T4R with CDD mode depending on the

RRH type connected.

− RRH-2LB/RRH-2UB : 2x2 MIMO

− RRH:-2WB : 4T4R with CDD (Matrix A/B + CDD mode)

y Optical interfacing with the RRH and Loopback Test

As the MRA-F contains a built-in Electrical to Optic (E/O) conversion device and an

Optic to Electrical (O/E) conversion device, it can send and receive ‘Digital I/Q and C

& M’ signals of the optical signals between distant RRHs.

The MRA-F can also run loopback tests to check whether the interface between the

MRA-F and RRHs is in good condition for proper communication.

The operator can run the loopback test if necessary using the WSM command.

Mobile WiMAX base station External Interface board assembly-Basic (MEI-B)

The MEI-B provides paths for alarm information that is generated from external devices

(additional equipment provided by the operator).

The MEI-B also collects alarms for the fan mounted on the DU to report to the MMA-G.