Ein Hardware-Demonstrator zur Konzeptverifikation eines JD-CDMA-Mobilfunksystems

Today's second generation mobile radio systems based on the GSM standard are not suited for the rapid growth of the number of users and the requirements to support high data rate services. Therefore, worldwide activities concerning the conception and standardisation of a further generation, the third generation of mobile radio systems, are presently carried out. The JD-CDMA mobile radio system considered in this thesis is an evolutional expansion of the pan European GSM standard and applies the multiple access schemes CDMA, FDMA and TDMA. Since February of 1998 JD-CDMA has been part of a European air interface standard for UMTS and a promising candidate for the world wide air interface standard IMT-2000. This thesis deals with the realisation of a hardware demonstrator, which consists of a base station and four mobile stations. The demonstrator is used for the concept verification of a JD-CDMA mobile radio system under laboratory conditions and in real mobile radio scenarios. The existing JD-CDMA concept is expanded by algorithms for power control and synchronisation. Because of the usage of a TDMA component GSM-like algorithms for synchronisation at link setup and synchronisation at link hold can be applied. Because of the joint detection no fast power control is necessary, but a GSM like slow power control is sufficient. The signalling between mobile station and base station is realised by complexity reduced GSM protocols, supplemented by the handling of the CDMA codes. Investigations on bit level show that low cost fixed point arithmetic is applicable for digital signal processing in JD-CMDA mobile radio systems. With a single state of the art digital signal processor the whole digital signal processing for eight CDMA codes within a time slot including channel decoding with a net data rate of 104 kBit/s in up- and downlink is carried out simultaneously. (orig.)Available from TIB Hannover: RS 849(1) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman