This is a recently revised second edition of an undergraduate textbook covering the techniques and principles of signal processing. Special attention is paid to the mathematical principles underpinning the techniques; Baher's opinion is that a robust understanding of the subject can only be built on mathematical foundations.

The core of the book covers standard topics within the subject;

• l Fourier series and the Fourier transform, which decompose an arbitrary time-series signal into its different frequency components
• l The Laplace transform, used to describe the behaviour of an analogue network or system
• l the Z transform, used to describe the behaviour of a digital network or system
• l analogue and digital filter design and realisation, using the Laplace and Z transforms respectively

These are not separate topics of study. Fourier series and the Fourier transform are very closely related, the Laplace transform is a generalisation of the Fourier transform and the Z-transform is strongly related to the Laplace transform. In consequence, similar but not identical concepts occur in different situations and a sound understanding of these topics can be surprisingly elusive. The net effect is somewhat akin to a hall of mirrors; there are often several different ways of explaining the reasons for some observed behaviour and while none are wrong, the poorer ones take a longer, reflected route to the truth. Baher is able to distinguish between original concept and reflection and this greatly aids both the conciseness and clarity of his presentation.

Overall, this book provides a comprehensive yet concise discussion of the principles of analogue and digital signal processing. Baher's personal mastery of the subject shines through and his presentation is clear and logical. Despite this, the mathematical nature of the subject matter makes large sections of the book hard going. This is not a criticism, but it is a warning; this book is emphatically not a casual read. That said, it is of sufficient quality to repay the intellectual investment. Recommended to the determined student.