This research study mainly focuses to develop an efficient channel estimation approach through swarm intelligence approach with lesser computational complexity. Orthogonal Frequency Division Multiplexing (OFDM) is a modulation approach used to fight with the selection of frequency of the transmission channels to attain high data rate without any disturbances. OFDM principle is to gain popularit...

The use of frequency-domain interleaving on a frame-byframe basis for orthogonal frequency division multiplexing (OFDM) combined with time division multiplexing (OFDM/TDM) is presented. In conventional OFDM, FDE is not designed to exploit the channel frequencyselectivity and consequently, the frequency diversity gain cannot be obtained. To further improve the bit error rate (BER) performance of...

Abstract: Orthogonal frequency division multiplexing combined with time division multiplexing (OFDM/TDM) was proposed to overcome the high peak-to-average-power ratio (PAPR) of conventional OFDM. Clipping and filtering can be used to further reduce the PAPR. OFDM/TDM with minimum mean square error (MMSE) frequency-domain equalization (FDE) requires accurate channel estimation (CE). In this pape...

For multiple-input multiple-output (MIMO) wireless communication system with minimum mean square error (MMSE) detection, a new scheme of power allocation between pilot and data symbols is investigated under MMSE channel estimation in this paper. First, we propose a novel soft-output MMSE MIMO detector by taking into consideration the channel estimation error. Then, through the application of ra...

The relative error-probability performance of three linear multiuser detectors—the minimum mean-square error detector, the decorrelator, and the conventional matched filter (MF) detector—is investigated under nonorthogonal signaling and additive white Gaussian noise conditions. It is shown that, contrary to the general belief, the minimum meansquare-error (MMSE) detector does not uniformly outp...

In this paper multi-user detection techniques, such as Parallel and Serial Interference Cancellations (PIC & SIC), General Minimum Mean Square Error (GMMSE) and polynomial MMSE, for the downlink of a broadband Multi-Carrier Code Division Multiple Access (MCCDMA) system are investigated. The Bit Error Rate (BER) and Frame Error Rate (FER) results are evaluated, and compared with single-user dete...

In this letter we propose a Minimum Mean Square Error (MMSE) Channel Impulse Response (CIR) estimator-aided Decision Directed Channel Estimation (DDCE) method, which is suitable for employment in both OFDM and MC-CDMA systems. Firstly, we outline the difficulty associated with the employment of the Least Squares (LS) approach to the problem of a posteriori Frequency Domain Channel Transfer Func...

This paper presents a general structure for Minimum Mean Square Error (MMSE) equalizers from which we can derive instances such as the: two proposed Linear Equalizers with Extrinsic Feedback (LE-EF), Linear Equalizer (LE) and Decision Feedback Equalizer (DFE). The Extrinsic Information Transfer (EXIT) chart was used to analyze the two proposed MMSE LE-EF receivers and their characteristics was ...

Two major training techniques for wireless channels are time division multiplexed (TDM) training and superimposed training. For the TDM schemes with regular periodic placements (RPP), the closedform expression for the steady-state minimum mean square error (MMSE) of channel estimate is obtained as a function of placement for Gauss-Markov flat fading channels. We then show that, among all period...

Frequency-domain equalization (FDE) based on minimum mean square error (MMSE) criterion is a powerful equalization technique for the broadband single-carrier (SC) transmission. However, the presence of timing offset produces the inter-symbol interference (ISI) and degrades the bit error rate (BER) performance. As the roll-off factor of the transmit filter increases, the performance degrades mor...