ICI Cancellation Techniques Based on Data Repetition for OFDM Systems

Abstract

Orthogonal frequency division multiplexing (OFDM), as a special case of multicarrier transmission, is an elegant solution to the problem of high date rate transmission. OFDM was first developed to transmit data streams without inter-symbol interference (ISI) and intercarrier interference (ICI) in the 1960s [1]. A big breakthrough for efficiently implementing the OFDM system was made in the 1970s, when discrete Fourier transform (DFT) was applied to perform baseband modulation and demodulation in OFDM [2]. Another breakthrough in OFDM is the emergence of cyclic prefix (CP) in the 1980s [3], which maintains orthogonality of the transmitted signals over multipath fading channels. In the 1990s, OFDM was exploited for wideband data communications. The first application in the commercial use of OFDM was digital audio broadcasting (DAB) in the 1980s and 1990s, where OFDM guarantees highly reliable data transmission over a high-velocity and complex environment. At the beginning of the 2000s, wireless local area network (WLAN) applied the OFDM technique to the physical layers [4]. In recent years, OFDM has been widely used for fourth generation (4G) and fifth generation (5G) wireless systems to increase the utilization of spectrum resources as well as to combat frequency-selective fading. The advantages of OFDM are summarized as follows: ● Resistance to frequency-selective fading ● Elimination of ISI and ICI ● Efficient use of the available spectrum ● Recovery of symbol lost by adequate channel coding and interleaving ● Enabling one-tap channel equalization However, every coin has two sides. The disadvantages of OFDM lie in the following: ● Large dynamic range of transmitted signal, or peak to average power ratio (PAPR) ● Sensitivity to carrier frequency offset (CFO) and Doppler