Interface Description EMII-800 Service Manual Application Information
EMII-800 V1.0 AnyDATA.NET Proprietary
Use Subject to Restrictions
3.3 Circuit Description
Ringer
MCP
(16M+4M)
Receptacle
Power Supply
AUDIO
Processor
Earpiece
Mic
MSM5100
[Figure 3-1] Block Diagram of Digital/Voice Processing Part
3.3.1 MSM Part
MSM5100, which is U401, is the core element of CDMA system terminal that includes ARM7TDMI
microprocessor core. It is made up of a CPU, encoder, interleaver, deinterleaver, Viterbi decoder,
MOD/DEM, and vocoder. MSM5100, when operated in the CDMA mode, utilizes CHIPX8
(9.8304MHz) as the reference clock that is received from IFR3000, and uses TCXO (19.68MHz) that is
received from TCX201. CPU controls the terminal operation. Digital voice data that have been inputted
are voice-encoded and variable-rated. Then, they are convolutionally encoded so that error detection and
correction are possible. Coded symbols are interleaved in order to cope with multi-path fading. Each data
channel is scrambled by the long code PN sequence of the user in order to ensure the confidentiality of
calls.
Moreover, binary quadrature codes are used based on Walsh functions in order to discern each channel.
Data created thus are 4-phase modulated by one pair of Pilot PN code and they are used to create I and Q
data.
When received, I and Q data are demodulated into symbols by the demodulator and then, de-interleaved
in reverse to the case of transmission. Then, the errors of data received from Viterbi decoder are detected
and corrected. They are voice decoded at the vocoder in order to output digital voice data.
