Overlap-save receivers for advanced DS-CDMA wireless systems

The cyclic-prefix overhead is one of the major drawbacks of existing Frequency Domain Equalizers (FDEs). In this thesis we propose a receiver structure for future generation DS-CDMA wireless systems that employs overlap-save processing to avoid the need for the cyclic-prefix overhead. The proposed Frequency Domain (FD) overlap-save receiver implements linear equalization using the Minimum Mean Square Error (MMSE) criterion and will provide multi-user detection capability at the Base Station (BS) of wireless systems. The proposed receiver can also be used for many of the existing legacy DS-CDMA systems. We performed an extensive set of simulations using 3GPP channel models and it is found that the performance of the FD overlap-save receiver is similar to that of the FD cyclic-prefix receiver. In this thesis we also analyzed and compared the complexity of both of these receiver structures. Lastly, we developed a rule of thumb to determine the size of the FFT block to use in the FD overlap-save system for the various data symbol rates.