The coding of channels is a core part of any communication network. Future wireless systems will need high performance codes with low complexity encoding and decoding in order to meet a wide variety of requirements, from running in highly dependable situations with short information messages and low code rates to running in high throughput scenarios with lengthy messages and high code rates. The investigation of polar codes in fading channels has important implications in the context of implementing polar codes in wireless communications. A significant development in the fields of information and coding theory, polar code allows for the flexible adjustment of code rates and block lengths without compromising error correction efficiency. Recently, the Third Generation Partnership Project (3GPP) New Radio (NR) group has supported polar codes to provide channel coding in the physical control channels of the 5G, wireless standard. Channel coding, which exists inside the physical layer, is essential in determining the latency and dependability of a communication system. However, error correction performance diminishes with shorter message durations. The polar encoding scheme can achieve channel capacity because it is based on the practical use of channel polarization operation. In this research, a polar code is included in the proposed system for data transmission over various multipath fading channel models (Nakagami-m, Rayleigh, and Lognormal fading channels) in the presence of AWGN, and in this design, the Successive Cancellation List (SCL) decoding algorithms for polar code are used in order for the suggested NR-polar QAM-OFDM system to perform better than the uncoded QAM-OFDM system. According to Monte Carlo simulations, QAM constellation NR-Polar-COFDM using LLRs computed due to the normal distribution over different types of channel PDFs performs better than the uncoded QAM-OFDM system in terms of bit error rat BER. To further enhance the system performance, CRC bits are used to enhance the efficiency of SCL decoding by improving distance characteristics. The simulation results show that BER is approximately 10-6 at SNR of 1dB in the AWGN channel, and in the multipath fading channel BER approaches 10-6 at SNR of 22.5dB in the Rayleigh and Nakagami-m fading channels, while in the lognormal fading channel at SNR of 14dB for short information block lengths at code rates (1/3) in the uplink and downlink control channels. The findings additionally confirm the superiority of Polar coding in the situation of transmitting information with short block lengths in the AWGN compared to the NR-LDPC-OFDM.