Amplitude modulation and Angle modulation are discussed in first two chapters. AM, FM, analysis equations, modulators, detectors, transmission and reception are thoroughly presented. SSB, DSB, VSB, FDM are also discussed. Noise theory is given in third chapter. It includes random variables, probability, random processes and correlation functions. Noise factor, noise temperature and mathematical analysis of noise is presented. Performance of modulation systems in the presence of noise is explained in fourth chapter. Figure of merit, capture effect and threshold effect are also presented. Last chapter presents information theory. Entropy information rate, discrete memoryless source, source coding, Shannon's theorems are also given in detail. Mutual information and channel capacity are also presented.