User's Manual

CHAPTER 2. Overview of SPI-2213
2-4 © SAMSUNG Electronics Co., Ltd.
2.3 Main Functions
The main functions of the SPI-2213 are as follows:
y Physical layer processing function
y Call processing function
y IP processing functions
y Auxiliary device interface function
y Convenient operation and maintenance function
2.3.1 Physical Layer Processing Function
OFDMA Ranging
The ranging supported by the OFDMA system is roughly divided by the uplink timing
synchronization method and the contention based bandwidth request method.
y Uplink Timing Synchronization
In the uplink timing synchronization method, the SPI-2213 detects the timing error of
the uplink signal by using the ranging code transmitted from MS and transmits the
timing correction command to each MS to correct the transmission timing of the
uplink. The uplink timing synchronization method has initial ranging, periodic ranging,
handover ranging, etc.
y Contention Based Bandwidth Request
In the contention based bandwidth request method, the SPI-2213 receives the
bandwidth request ranging code from each MS and allocates uplink resources to the
corresponding MS to enable to transmit the bandwidth request header.
The contention based bandwidth request method has bandwidth request ranging or
something.
Channel Encoding/Decoding
The SPI-2213 carries out the Forward Error Correction (FEC) encoding for the downlink
packet created in the upper layer by using Convolutional Turbo Code (CTC).
On the contrary, it decodes the uplink packet received from the MS after demodulating.
Modulation/Demodulation
The SPI-2213 carries out the FEC encoding for the downlink packet created in the upper
layer and modulates the encoded packet into the QAM signal. In addition, the SPI-2213
demodulates and decodes the uplink packet received from MS.