An Overview of Mimo Ofdm System for Wireless Communication

Abstract

In modern days, we are using wireless modern communication systems, which require high data rates and more band width efficiencies. The most well-known 4G technology of wireless standard is Long Term Evolution (LTE) which espoused OFDMA (Orthogonal Frequency Division Multiple Access) and MIMO (Multi Input Multi Output) techniques. These techniques are employed on downlink of LTE. A MIMO system utilizes numerous antennas at both the transmitter and receiver to work on the performance of the correspondence system using diversity and multiplexing methods. MIMO framework gives higher phantom effectiveness, further develops unwavering quality, decreases fading and further develops protection from interference. In this paper we give an overview of the MIMO, OFDM and MIMO-OFDM system for wireless communication.

A Novel Alternating μ-Law Companding Algorithm for PAPR Reduction in OFDM Systems

“…Similar to case 1, from Figure 4, we can find the interval of x[n] that satisfies the inequality Equation (10). Therefore, when λ > 1 , the x[n] will be expressed as…”

“…In light of this, it is inevitable to evolve from single-carrier to multi-carrier technology [6]. Also, among multi-carrier technologies, orthogonal frequency division multiplexing (OFDM) possesses the characteristic of overlapping and mutually orthogonal subcarriers, thereby enhancing spectral efficiency (SE), prompting the robustness of resistance against multipath interference and inter-symbol interference (ISI) [7], and OFDM has been the most popular and mature vital technology in advanced wireless communication systems [8][9][10][11]. Unfortunately, OFDM bears the inherent nature of a multi-carrier system; therefore, the issue of peak-to-average power ratio (PAPR) is inevitable.…”

The Impact of Diverse Jamming Schemes against LTE-based Remote Detonation Devices

“…OFDM transmission technology is considered efficient in the frequency selective channel because it converts the wideband to several sub-bands with a flat fading channel effect. So, the complex equalization needed in the receiver to overcome the frequency selective fading channel effect can be replaced by a simpler equalization process [14]. But, the main disadvantage of OFDM technology is the high sensitivity to CFO which is caused by asynchrony between the receiver's down-conversion local oscillator frequency and the receiving OFDM signal carriers.…”

Performance Analysis of Combining Beamforming and ZF/MMSE-SIC Equalization Techniques for MIMO DWPT-COFDM Systems

“…Simultaneously, Orthogonal Frequency Division Multiplexing (OFDM) and its variants like Coded OFDM (COFDM) have gained widespread adoption in wireless networks [4][5][6][7][8]. When coupled with Multiple Input Multiple Output (MIMO) spatial multiplexing, these systems deploy multiple antennas at each end, enhancing capacity and spectral efficiency [9][10][11][12][13]. They rely on the Inverse Fast Fourier Transform (IFFT) and Fast Fourier Transform (FFT) algorithms, which have drawbacks, including side-lobes due to a rectangular window and the need for a Cyclic Prefix (CP) to mitigate ISI, consuming 25% bandwidth [14][15][16][17].…”