Digital IF filter technology for 3G systems: an introduction

Abstract

Contemporary digital communication systems such as those ABSTRACT being developed for the deployment of third-generation cellular require ever increasing performance levels in their signal processing chains to extract higher data rates and to provide decreasing price/performance ratios. Additionally, communication systems like 3G that must support multimode flexibility, such as the software radio, must be able to reconfigure their signal processing chains while keeping circuit complexity to a minimum. Given these constraints, DSP is the only viable alternative for baseband processing and digital IF processing. DSP is in many cases the only viable alternative to analog IF processing. Digital IF affords greater flexibility and higher performance in terms of attenuation and selectivity. It also offers better time and environment stability and lower equipment production costs than traditional analog techniques. opment oftware radio and digital intermediate frequency S (IF) technology are enabling the economic develof third-generation cellular base stations by providing the required flexibility and fidelity at reasonable price points. Digital signal processing (DSP) affords greater flexibility and higher performance (in terms of attenuation and selectivity) than traditional analog techniques. It also offers better stability over time and environmental parameters with lower equipment production costs. Additionally, components available today let DSP extend from baseband to intermediate frequencies. This makes DSP useful for tuning, signal selection, and frequency up-and downconversion.

The digital front-end of software radio terminals

“…Still, by combining downconversion and channel filtering in filter banks the effort can be lowered, especially in narrowband systems. Particularly, if only signals of one standard are to be received, discrete Fourier transform (DFT) filter banks are promising candidates as channelizers, since all channels have the same bandwidth [19,20]. Polyphase filter banks [8,21], one subclass of uniform DFT filter banks, have the desirable characteristic that the relative complexity tends to decrease as the number of channels to be separated increases, in contrast to the parallel implementation of one-channelchannelizers.…”

Evolving Mobile Networks

“…Thus, while compatibility between standards remains attractive, SDRs will shape into software and hardware reconfigurable radios in the RF, Intermediate Frequency (IF), as well as baseband processing stages [29][30][31][32].…”

Investigation of multirate techniques for digital generation of transmitter signals for TIGER radar

“…FIR digital filters are linear phase filters with very narrow transition band. The symmetric and linear properties of FIR filter make it attractive for communication systems [3].…”