No abstract

Robustness and reliability are more important for future applications than today. This is outlined in this paper. The suitability of the spread-spectrum technology for future wireless applications is investigated. The spread-spectrum technology offers the RAKE receiver structure to mitigate the most harmful type of interference in a mobile application, the multipath interference. To enhance the spectral efficiency multi-code transmission is employed. It is easy and inexpensive to adapt the system to the channel delay spread and avoid expensive channel equalization techniques. The extension from a point-to-point topology to a multipoint-to-point topology is achieved with the code-division-multiple-access concept. The bandwidth efficiency can be further enhanced using multiuser detection. For interference limited environments the multicarrier code-division multiple access scheme is applied. Special attention is payed to the multi-code transmission and the related improvement in spectral efficiency.