The Channel Sounder is used to determine the time-variant impulse response of mobile radio channels. The most important characteristics of the propagation channel are delay spread and Doppler spread. To measure these two parameters one needs to have an advanced spread spectrum sounding system with variable code rate and code length using state of art technology.
The measurement system, the All Digital Channel Sounder, uses spread spectrum technology, and the operator of the Sounder is able to easily change the spreading code by programming the Universal Signal Generator with any kind of spreading sequences.
The design of the Sounder is based on a programmable sequence generator, 900 MHz RF, GPS frequency reference receivers, 70 MHz IF, direct sampling of the IF signal, very high speed SHARP LH9124 and AT&T 32C DSP chipsets, 486 host PC, and SCSI data storage.