JPL's Wireless Communication Reference Website

Chapter: Analog and Digital Transmission Section: Spread Spectrum

Conclusions

contributed by Jack Glas, Lucent.

In this section the relation between the data detection input SNR and the BER was made for both an Additive Gaussian Noise Channel and a Multi-Path Channel in a DS/FH system like WISSCE . This was done in two steps: we started with discussing the SNR degradation due to non-ideal despreading and MA-interference. Secondly the relation between the SNR and the BER was explained. A difference with a usual BER-analysis is the usage of the data-detection input SNR as a reference value. In WISSCE the bandwidth at this stage in the receiver is about 1.3 MHz. As a consequence, proper SNR values are below 0 dB.

It appeared that WISSCE has to operate in a slowly fading channel . It is however difficult to catch the channel properties in a typical description. This is illustrated in figure 5, the different curves show the relation between SNR and BER for various values of the strength of the line-of-sight path.

Further Reading


JPL's Wireless Communication Reference Website © Jack P.F. Glas (Author) and Jean-Paul M.G. Linnartz (Editor), 1993, 1995, 1999