A low-complexity standard transmit diversity scheme for coded orthogonal frequency division multiplexing (OFDM) frameworks is cyclic delay diversity (CDD). As the cyclic delay esteem expands the diversity effect also increases. However, the channel estimation turns out to be more troublesome because of increased frequency selectivity as the increased cyclic delay value. In this paper we discussed about dissimilar channel estimation schemes and to conclude we proposed a novel pilot-aided channel estimation scheme for CDD to estimate the channel in an enhanced way. Our scheme estimates each channel separately and achieves significant performance improvement.

Orthogonal Frequency Division Multiplexing (OFDM) is a multicarrier transmission technique which has the major drawback namely Peak to Average Power Ratio (PAPR). The high PAPR influences the efficiency of the power amplifier. The Selected Level Mapping (SLM) gives reduced PAPR contrasted with different strategies but the complexity is high due to the necessity of various Inverse Fast Fourier Transform (IFFTs). With the end goal to reduce the complexity, the proposed design requires only one IFFT, the candidate signals are produced by cyclic shifting the original time domain signal then multiplying with the distinctive genuine positive numbers. At that point the candidate with most minimal PAPR is chosen for transmission.