Frequency Domain Interference Cancellation With DFE For CDMA

CDMA (Code Division Multiple Access) System differentiates several users by using orthogonal code, or Quasi-orthogonal code. Under the condition of the same frequency and the same time, the various receivers filter out the target signal according to the discrepancy of the code-shape. CDMA becomes one of the main streams in the 3rd generation mobile communication systems due to its several attractive features, such as high spectrum efficiency, high capacity, simple frequency deployment, excellent privacy ability, multi-path fading mitigation, macro-diversity and soft hand-off, etc. However, CDMA network is a self-interference system, because of the non-ideal nature of the radio propagation environment, which yields the Inter-symbol Interference (ISI). At the same time, the orthogonality of the code is affected seriously, so that one user's signal becomes the interference of others, which is called Multiple-Access Interference (MAI), then it's harder for the receivers to pick out the target signal, afterwards, limit the overall system capacity.This dissertation focuses on wireless related technology, including frequency-domain equalization and interference cancellation. Based on the CDMA system architecture, it proposes an improved frequency domain interference cancellation method, which integrates the equalization and inter-leave technology.This dissertation has finished the following tasks:it proposes an advanced interference cancellation method, combined with equalization and inter-leave technology. Then the paper devises the simulation platform and verifies the result. By comparing with the traditional receiver—Rake receiver, the new proposed algorithm performs much better. In addition, it is very important and useful for applications in which the frame structure is predefined and can not be changed.