Bit-Interleaved Coded Modulation (BICM) is a coding technique that combines the advantages of signal-space coding with the flexibility of binary codes. It allows for the use of powerful binary codes in various modulation formats, making it a versatile approach for achieving high spectral efficiency in communication systems. BICM is widely used in modern systems such as DSL, Wireless LANs, WiMax, and others, and is considered the de facto standard for coding over Gaussian channels. The theoretical foundation of BICM is based on error exponents and information theory. It is analyzed within the framework of error exponents for mismatched decoding, allowing for accurate analysis without assumptions about the length of the interleaver or independence between bits. The BICM capacity is studied in relation to the signal-to-noise ratio (SNR), and the wideband regime is characterized. Efficient tools for error probability analysis are reviewed, including bounds that improve upon the union bound in the region beyond the cutoff rate. BICM with iterative decoding is also discussed, focusing on techniques such as extrinsic information transfer charts, the area theorem, and code design via curve fitting. The monograph also covers applications of BICM beyond classical Gaussian channels, including non-coherent demodulation, block-fading, MIMO, and optical communication. The chapter on channel models and code ensembles provides the background for the rest of the monograph, including the Gaussian channel model and the analysis of coded modulation schemes. The information-theoretic foundations of BICM are reviewed, along with its capacity, cutoff rate, and error exponents. The error probability of BICM is analyzed, with a focus on the union bound and improved bounds. The monograph also discusses the iterative decoding of BICM, including design techniques and improved schemes. Finally, applications of BICM in various communication scenarios are described.Bit-Interleaved Coded Modulation (BICM) is a coding technique that combines the advantages of signal-space coding with the flexibility of binary codes. It allows for the use of powerful binary codes in various modulation formats, making it a versatile approach for achieving high spectral efficiency in communication systems. BICM is widely used in modern systems such as DSL, Wireless LANs, WiMax, and others, and is considered the de facto standard for coding over Gaussian channels. The theoretical foundation of BICM is based on error exponents and information theory. It is analyzed within the framework of error exponents for mismatched decoding, allowing for accurate analysis without assumptions about the length of the interleaver or independence between bits. The BICM capacity is studied in relation to the signal-to-noise ratio (SNR), and the wideband regime is characterized. Efficient tools for error probability analysis are reviewed, including bounds that improve upon the union bound in the region beyond the cutoff rate. BICM with iterative decoding is also discussed, focusing on techniques such as extrinsic information transfer charts, the area theorem, and code design via curve fitting. The monograph also covers applications of BICM beyond classical Gaussian channels, including non-coherent demodulation, block-fading, MIMO, and optical communication. The chapter on channel models and code ensembles provides the background for the rest of the monograph, including the Gaussian channel model and the analysis of coded modulation schemes. The information-theoretic foundations of BICM are reviewed, along with its capacity, cutoff rate, and error exponents. The error probability of BICM is analyzed, with a focus on the union bound and improved bounds. The monograph also discusses the iterative decoding of BICM, including design techniques and improved schemes. Finally, applications of BICM in various communication scenarios are described.