# Efficient and Robust Image Communication Techniques for 5G Applications in Smart Cities
###### Abstract  
A wide range of multimedia applications must be supported by the modern fifth generation (5G) wireless communication systems for realizing the diverse applications in smart cities. The diverse applications such as real-time monitoring of roads, smart homes, smart industries, etc., for a sustainable smart city emphasizes a robust and efficient image transmission. In this paper, the influence of maximal ratio combining (MRC) on the reception of images with different orthogonal frequency division multiplexing (OFDM) versions is studied. The different OFDM versions considered here are the fast Fourier transform (FFT) based OFDM and discrete cosine transform (DCT) based OFDM. A comparison between diverse modulation levels for the images transmitted through different OFDM methodologies, along with variation in a number of receiving antennas for MRC, is proposed for additive white gaussian noise (AWGN) and Rayleigh fading channels. The diverse modulation levels used are binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), 8-PSK, and 16-PSK. The parameters that are used to compare different versions of OFDM for MRC antenna configurations are signal-to-noise ratio (SNR) vs. bit error rate (BER) and peak signal-to-noise ratio (PSNR) at the receiver as an estimation parameter for the received image quality.  
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existence of inter-carrier interference (ICI) and inter-symbol interference (ISI) [2] Besides, elevated BER the OFDM system also experiences the problem of high PAPR, which occurs due to the non-linear operations of the power amplifiers installed at the transmitter side.  
To mitigate such problems, various hybrid schemes are implemented in combination with OFDM systems. One of them is the use of various space diversity techniques, i.e., transmit diversity and receiver diversity. Multiple antennas are installed at the transmitter side to transmit diversity, whereas, in receiver diversity, the receiver side is being equipped with multiple antennas [3]. Diversity reception is the most widely used methodology utilized in advanced wireless communication systems like OFDM, WiMAX, Wideband code division multiple access (WCDMA), and multiple input multiple output (MIMO). One of the prime diversity reception techniques is diversity combining multiple antennas only at the receiver side. Diversity combining techniques are further classified into three categories, i.e., MRC, Equal Gain Combining (EGC), and Selection Combining (SC). MRC is the standout performer that performs much better than other combining schemes [4; 5]. Image and Video transmission are a major application area of wireless communication systems. The concept of building a smart city is based on making efficient use of resources and transmission of real-time information from one place to another quickly in a very robust way. The paper's proposed methodology emphasizes efficient transmission of images from one place to another with minimum possible errors, making it most suitable for sustainable smart city applications like smart homes, smart industries, robotics and automation, smart roads, etc.  
The remaining manuscript is organized as follows: Section 2 presents the state of the work, whereas Section 3 discusses the FFT-OFDM and DCT-OFDM system model. Section 4 provides the proposed system model and parameters. Section 5 highlights the significant results and comparative analysis. Section 6 exhibits the concluding remarks.