User's Manual

Mobile WiMAX RAS SPI-2L10 System Description/Ed.00

3-5

In addition, by using the TSCM-I, which is a slave board embedded in the IEEE 1588

function, the M2DA-A receives the timing information which is transmitted via the

Ethernet network from the IEEE 1588 master and generates reference clocks using the

received timing information.

The generated reference clocks are regenerated as the clocks necessary for each block

within the M2DA-A, and are distributed to them. These clocks are used to maintain

internal synchronization in the SPI-2L10 and operate the system.

M2RU-2W

The M2RU-2W is a unified RF board that carries out the transceiver, power amplifier, TDD

switch, and Low Noise Amplifier (LNA) functions in the SPI-2L10.

y Downlink (Tx) Signal Processing

The M2RU-2W converts the baseband signals received from the M2DA-A to analog

IF signals through Digital-to-Analog Conversion (DAC). These analog IF signals are

again frequency upconverted into signals of RF bandwidth and then sent to the power

amplifier. The power amplifier performs power amplification on those received signals

of RF bandwidth and then sends them to the filter. The filter suppresses spurious

radiation, except the received RF signals within the RF signal bandwidth, and then

sends those RF signals through the antenna.

At this time, the strength of the RF signals sent per Tx path is 4 W at the RF output

port.

y Uplink (Rx) Signal Processing

The filter suppresses spurious radiation, except the RF signals, which are received

through the antenna, within the RF signal bandwidth. The received signals are filtered

and are low noise amplified by the LNA, and then down converted into IF signals.

The converted IF signals undergo Analog-to-Digital Conversion (ADC) to obtain

baseband signals, and then are sent to the M2DA-A.

y TDD Operation

The M2RU-2W includes a TDD switch. The TDD switch of the M2RU-2W receives

TDD signals from the M2DA-A and performs switch-over for sending and receiving

paths to make the SPI-2L10 operate as a TDD system.

The TDD switch sends the received TDD signal to the power amplifier so that it can

operate in the Tx section.