Polyphase up converter channelizers enable fully digital multi-carrier frequency hopping modulators

Frequency hopping (FH) is a spread spectrum transmission technique that achieves frequency diversity gain over frequency selective fading channels and also has a low probability of interception. This technique has been widely used in military applications, for its recognized anti-jamming performance, and in some wireless standards such as GSM and Bluetooth, for its interference resistance. Modern FH systems employ partial digital technology and their performance depends on the hopping bandwidth. The wider is the hopping bandwidth the greater is the performance. The width of the hopping bandwidth is one of the factors that limits the usage of fully digital technology for FH systems. In [7] we proposed a fully digital FH architecture based on polyphase channelizers. In this paper, we extend the proposed transmitting architecture to a multi-carrier frequency hopping (MCFH) system. The proposed structure is composed of a cascade of two polyphase up converter channelizers. The first one performs the M-FSK (or BFSK) modulation while the second one accomplishes the task of hopping the modulated spectra independently over L subcarriers under the control of pseudorandom sequence generators. In this paper, both theoretical aspects and simulation results, demonstrating the effectiveness of the proposed fully digital structure, are provided.