Over the last few decades wireless communications, especially Mobile Communication Technology, has evolved by leaps and bounds. The mobile communication industry has named the different major changes as generations namely 1G, 2G,..5G. We are presently looking at deployment of 5G technologies. The work for 6G has already started. This book is focused on the waveform design of 6G. It presents a discourse on a potential waveform for 6G namely Orthogonal Time Frequency Space (OTFS) modulation. OTFS has a distinct feature when compared to earlier generation waveforms such that information bearing signal is placed in the delay Doppler domain as opposed to the usual placement of such signals in the time-frequency domain. This unique feature of OTFS enables it to overcome several disadvantages of a very popular and highly successful waveform namely Orthogonal Frequency Division Multiplexing (OFDM). OTFS is known to be more resilient to frequency offset and Doppler which is one of the key drawbacks of OFDM. With this feature, OTFS, can support higher mobility as well as higher frequency bands of operation which is also one of the key requirements of the next generation wireless communication technologies. The implementation complexity of OTFS remains comparable to that of OFDM. It is found that OTFS provides significant SNR advantage, higher resilience, lower PAPR, lower out of band signal leakage and higher multi-user spectral efficiency than that of OFDM. This book addresses * Fundamental signal model of OTFS. * Receiver design for OTFS * Channel estimation in OTFS * Multiple Access through non-orthogonal multiple access (NOMA-OTFS) The contents of the books are primarily outcome of the research work done at the G. S. Sanyal School of Telecommunications, Indian Institute of Technology Kharagpur, Kharagpur, India. Orthogonal Time Frequency Space Modulation : A waveform for 6G is ideal for personnel the wireless communication industry as well as academic staff and master/research students in electrical engineering with a specialization in wireless communications.

Over the past few decades, wireless access networks have evolved extensively to support the tremendous growth of consumer traffic. This superlative growth of data consumption has come about due to several reasons, such as evolution of the consumer devices, the types of telephone and smartphone being used, convergence of services, digitisation of economic transactions, tele-education, telemedicine, m-commerce, virtual reality office, social media, e-governance, e-security, to name but a few. Not only has the society transformed to a digital world, but also the expectations from the services provided have increased many folds. The last mile/meters of delivery of all e-services is now required to be wireless. It has always been known that wireless links are the bottleneck to providing high data rates and high quality of service. Several wireless signalling and performance analysis techniques to overcome the hurdles of wireless channels have been developed over the last decade, and these are fuelling the evolution of 4G towards 5G. Evolution of Air Interface Towards 5G attempts to bring out some of the important developments that are contributing towards such growth.

The next generation mobile communication networks (4G) have the challenging target of The next generation mobile communication networks (4G) have the challenging target of providing a peak data rate of 1 Gigabit per second local area and 100 Megabit per second wide area. The ability to offer such high data rates in 100MHz bandwidth requires overall a very high spectral efficiency, and hence the need for multi-antenna techniques (MIMO) with spatial multiplexing, fast dynamic link adaptation and packet scheduling, wideband access techniques, and most likely non-contention based spectrum sharing among multiple operators. Many of these required technology components and techniques are well researched and established. Adaptive PHY-MAC Design for Broadband Wireless Systems explains how one can integrate and optimise their use in providing the target cell data rates with high availability. The authors address the ability to cope with interference and enhanced physical layer processing, and simultaneously, the multifaceted system level design. Focus is also on the selection of technology components and techniques, which leads to the highest spectral efficiency and peak data rate availability with reasonable Quality of Service (QoS) support, such as improved outage scenario, reduced delay, guaranteed bit rate, etc. In short, this book will answer questions such as, how individual techniques relate to each other, how can we benefit the gains by suitable combinations of different technologies and how to choose different technological solutions in different scenarios, etc. The next generation mobile communication networks (4G) have the challenging target of The next generation mobile communication networks (4G) have the challenging target of providing a peak data rate of 1 Gigabit per second local area and 100 Megabit per second wide area. The ability to offer such high data rates in 100MHz bandwidth requires overall a very high spectral efficiency, and hence the need for multi-antenna techniques (MIMO) with spatial multiplexing, fast dynamic link adaptation and packet scheduling, wideband access techniques, and most likely non-contention based spectrum sharing among multiple operators. Many of these required technology components and techniques are well researched and established. Adaptive PHY-MAC Design for Broadband Wireless Systems explains how one can integrate and optimise their use in providing the target cell data rates with high availability. The authors address the ability to cope with interference and enhanced physical layer processing, and simultaneously, the multifaceted system level design. Focus is also on the selection of technology components and techniques, which leads to the highest spectral efficiency and peak data rate availability with reasonable Quality of Service (QoS) support, such as improved outage scenario, reduced delay, guaranteed bit rate, etc. In short, this book will answer questions such as, how individual techniques relate to each other, how can we benefit the gains by suitable combinations of different technologies and how to choose different technological solutions in different scenarios, etc. The next generation mobile communication networks (4G) have the challenging target of The next generation mobile communication networks (4G) have the challenging target of providing a peak data rate of 1 Gigabit per second local area and 100 Megabit per second wide area. The ability to offer such high data rates in 100MHz bandwidth requires overall a very high spectral efficiency, and hence the need for multi-antenna techniques (MIMO) with spatial multiplexing, fast dynamic link adaptation and packet scheduling, wideband access techniques, and most likely non-contention based spectrum sharing among multiple operators. Many of these required technology components and techniques are well researched and established. Adaptive PHY-MAC Design for Broadband Wireless Systems explains how one can integrate and optimise their use in providing the target cell data rates with high availability. The authors address the ability to cope with interference and enhanced physical layer processing, and simultaneously, the multifaceted system level design. Focus is also on the selection of technology components and techniques, which leads to the highest spectral efficiency and peak data rate availability with reasonable Quality of Service (QoS) support, such as improved outage scenario, reduced delay, guaranteed bit rate, etc. In short, this book will answer questions such as, how individual techniques relate to each other, how can we benefit the gains by suitable combinations of different technologies and how to choose different technological solutions in different scenarios, etc.