Gsm/Cdma Mobile Communication Terminal Experimental System

The mobile communication experimental system is designed for the curriculum of mobile communications, enabling students to master the techniques of current mobile communication such as terminal technique and network technique. The mobile communication terminal system comprises the following parts: signal source encoding, signal channel encoding, modulation and demodulation; the network system comprises system experiments and 900MHz GSM mobile phone system experiments.


1. Mobile terminal
Comprising the following units, which are designed with self independency and can be interconnected to configure more complex system.
1) Audio I/O interface (earphone and mike)
2) DC level controller
3) PCM/ADPCM encoder
4) LPC voice companding encoder
5) Signal channel coding/decoding, framing and DSP modulation/demodulation
6) Signal channel generator
7) Wireless transmitting/receiving RF


Signal source encoding:

  • Signal source encoding 1 - Encoding of PCM, ADPCM and signal source parameters
  • Signal source encoding 1 - Encoding of AMBE voice compression

Signal channel encoding:

  • Linear block codes + interleaving + deinterleaving
  • Convolutional codes
  • Scrambling and descrambling
  • Loop codes

Modulation and demodulation:

  • GMSK modulation and demodulation
  • QPSK modulation and demodulation
  • CDMA frequency spread
  • CDMA de-spread (Address codes capture)

Signal channel:

  • Simulation of mobile channel (Gaussian, Multipath, Ricean and Rayleigh fading)
  • Mobile channel balance
  • TDM, FDM and CDM


  • GSM frame structures
  • GSM mobile station access grant
  • GSM mobile station calling
  • GSM mobile station called
  • GSM mobility management

900MHz GSM

  • Calling, being called, sending/receive short message and GPRS data transfer, etc. Dual-development can be performed with the hardware provided in this system on the platform which is composed of two DSP, FPGA module, display screen and keyboard.