Browsing by Author "Bejide, Emmanuel Oluremi"

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Open Access
    An Iterative Multiuser Detector for Turbo-Coded DS-CDMA Systems
    (Biomed Central, 2005) Bejide, Emmanuel Oluremi; Takawira, Fambirai
    We propose an iterative multiuser detector for turbo-coded synchronous and asynchronous direct-sequence CDMA (DS-CDMA) systems. The receiver is derived from the maximum a posteriori (MAP) estimation of the single user's transmitted data, conditioned on information about the estimate of the multiple-access interference (MAI) and the received signal from the channel. This multiple-access interference is reconstructed by making hard decisions on the users' detected bits at the preceding iteration. The complexity of the proposed receiver increases linearly with the number of users. The proposed detection scheme is compared with a previously developed one. The multiuser detector proposed in this paper has a better performance when the transmitted powers of all active users are equal in the additive white Gaussian noise (AWGN) channel. Also, the detector is found to be resilient against the near-far effect.
  • Thumbnail Image
    Item
    Open Access
    Performance of turbo coded DS-CDMA systems in correlated and uncorrelated satellite communication channels
    (2006) Gule, Nkosinathi; Bejide, Emmanuel Oluremi
    This thesis aims at presenting the perfonnance of turbo codes in the correlated and uncorrelated satellite fading channel. Turbo codes are known to give very good perfonnance results in A WGN channels, especially for very large input message length codes or interleaver sizes. It can be shown that good perfonnance of the turbo codes can be achieved with small interleaver sizes in a satellite channel.
  • Thumbnail Image
    Item
    Open Access
    Performance of turbo multi-user detectors in space-time coded DS-CDMA systems
    (2007) Mashwama, Derrick Bonginkosi; Bejide, Emmanuel Oluremi
    In this thesis we address the problem of improving the uplink capacity and the performance of a DS-CDMA system by combining MUD and turbo decoding. These two are combined following the turbo principle. Depending on the concatenation scheme used, we divide these receivers into the Partitioned Approach (PA) and the Iterative Approach (IA) receivers. To enable the iterative exchange of information, these receivers employ a Parallel Interference Cancellation (PIC) detector as the first receiver stage.