32 research outputs found
Receiver design for the uplink of base station cooperation systems employing SC-FDE modulations
The presented paper considers the uplink transmission in base station (BS) cooperation schemes where mobile terminals (MTs) in adjacent cells share the same physical channel. We consider single-carrier with frequency-domain equalization (SC-FDE) combined with iterative frequency-domain receivers based on the iterative block decision feedback equalization (IB-DFE). We study the quantization requirements when sending the received signals, from different MTs, at different BSs to a central unit that performs the separation of different MTs using iterative frequency-domain receivers. Our performance results show that a relatively coarse quantization, with only 4 bits in the in-phase and quadrature components of the complex envelope already allows close-to-optimum macro-diversity gains, as well as an efficient separation of the transmitted signals associated with each MT
Turbo-coded OFCDM systems for 4G mobile communications
In this paper, a hybrid multicode interference cancellation (MCI) and minimum mean square error (MMSE) detection scheme is presented for the turbo-coded orthogonal frequency and code division multiplexing (OFCDM) systems. The weights of hybrid detection are derived theoretically and an effective method to generate the weights in practical applications is proposed. By means of computer simulation, it is shown that to carry out interference regeneration for the hybrid detection, the conventional turbo decoding algorithm should be extended to decode parity bits as well. Moreover, two iterations in turbo decoding are sufficient to provide good performance for the system with the multistage hybrid detection. Finally, the proposed method for MMSE weight estimation works well with properly chosen parameters.link_to_subscribed_fulltex