Like many wireless systems, Orthogonal Frequency Division Multiplexing (OFDM) needs proper allocation of limited resources such as total transmit power and available frequency bandwidth among the users to meet their service requirements. In this paper, different versions of two evolutionary approaches, Differential Evolution (DE) and Particle Swarm Optimization (PSO) have been applied for adapt...

Abstract In this paper, we propose a signal processing method in passive radar using the multi-user (MU) multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) as illuminator of opportunity. The MU-MIMO-OFDM modulation is adopted fifth-generation (5G) communication. We consider scenario where multiple mobile users share same time–frequency resources but separate...

Optimal training design and channel estimation for spatially correlated multi-user multi-input multi-output with orthogonal frequency-division multiplexing (MIMO-OFDM) systems is still an open research topic of great interest. This study first applies tractable semi-definite programming (SDP) to obtain the optimal training signal for the general case of spatial channel correlations for multi-us...

This paper proposes the assignment of resource blocks (RBs) to reduce the peak-to-average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) in a multi-user OFDM system. This system ranks the users according to the channel state information (CSI) for RB assignment. In our proposed technique, an RB is assigned to either the firstor second-ranked mobile station (MS) to minimi...

The demand for high-speed mobile wireless communications is rapidly growing. OFDM technology promises to be a key technique for achieving the high data capacity and spectral efficiency requirements for wireless communication systems of the near future. In our proposed method Adaptive modulation techniques is used for maximizing the data throughput of subcarriers allocated to a user. It measures...

In the context of orthogonal frequency division multiplexing (OFDM), most papers define OFDM symbol synchronization as frame synchronization. In this paper, a frame is defined as a block of several OFDM symbols in the time dimension. The main contribution of this work is to propose a novel, lowcomplexity, frame synchronization method for multi-carrier systems that does not require any transmiss...

In code division multiple access CDMA systems direct sequence DS applying maximum ratio combining MRC at the receiver has achieved high interest for mobile communications A second and rather novel technique is orthogonal frequency division multi plexing OFDM applying maximum likelihood detection MLD at the receiver In this paper the performance of both tech niques is compared considering the mo...

. Orthogonal Frequency division multiplexing (OFDM) has recently been proposed for use in high data-rate wireless systems. OFDM has an important property of spectrum utilization technique that distributes each tone, which is orthogonal with every other tone. The system capacity can be significantly improved by multiple transmit and receive antennas that are used to form Multi-input multi-output...

In this paper, we evaluate the performance of filter bank-based multi-carrier with offset quadrature amplitude modulation (FBMC/OQAM) for the multi-user multiple-input multiple-output (MIMO) uplink in the presence of timing and frequency misalignments. In such a scenario, multiple access is achieved by assigning groups of sub-carriers to user nodes. The nodes are equipped with multiple antennas...

In this paper, the performance of Dicrete Wavelet Transform (DWT) based Multi-user MIMO-OFDM is compared with the performance of FFT based MIMO-OFDM system. Wavelet based OFDM has lot of advantages compared to the FFT based OFDM. There is no need for cyclic prefix, flexibility and optimal resolution. Wavelets existed suitably in almost all the arenas of wireless communication schemes with OFDM ...