Reduction of radio emission in low frequency WCDMA

The exposure to electromagnetic radiation is a critical point for the acceptance and market penetration of future mobile telecommunication systems. For Universal Mobile Telecommunication Systems (UMTS) one of the significant factors for the radio emission is the power of the primary common pilot channel (CPICH). It is continuously radiated throughout the entire network evoking permanent interference. On the other hand the received power of the CPICH determines the coverage area of the cells and therewith their radii. A reduction of the CPICH power would inevitably result in less coverage, unless a lower frequency band is utilised for its better radio propagation properties. We show that by using lower frequency bands the emission power of the CPICH can be decreased by about 16 dB and consequently the radiation density of the whole base station by about 13 dB without affecting the guaranteed network coverage.