ADC and DSP challenges in the development of software radio base stations

Abstract

The need for software-defined radios raiscs a number of tcchnical challcngcs, which play a significant role in the development of third-generation personal communications systems (PCS). Some of the most important tcchnical challenges deal with analog-to-digital conversion and digital signal processing tcchnologics, which, in many cascs, cannot provide the advanced hardware ncedcd to support the dcmanding PCS tclccommunications services. In this articlc, we discuss thcsc two tcchnical challenges, focusing primarily on hase station radio systcms. We first idcntify the most important requirements for ADC and DSP technologies, and we then extcnsively discuss and/or propose enabling schemes that could relax thcsc rcquircmcnts and aid thc implcmcntation of software radio base stations.Furthermore, wc discuss new structurcs thill can support the dcvclopincnt of physically distrihutcd base stations.

Experimental Study of DQPSK Modulation on SDR Platform

“…The largest computational requirement is on the receiver side especially on filter part in channelization, which ranges from 100 to 200 operations/sample [3,5,6]. Applying the sampling speed of 22.5 MHz will result in 22.5 MSPS, so that it needs 2,250 -4,500 MIPS.…”

A statistical approach to estimate the dynamic non-linearity parameters of pipeline ADCs

“…These modern communication systems with the ultimate goal of directly digitizing the RF signal [1] will require high-resolution highlylinear ADCs [2,3]. This is due to the wide bandwidth of the signal and the density of signal information.…”

“…This is due to the wide bandwidth of the signal and the density of signal information. The dynamic range of an ADC is mostly expressed by the spurious-free dynamic range (SFDR) [2], and signal to noise and distortion ratio (SNDR). The SFDR of an ADC is defined as the difference in decibel, between the full-scale fundamental tone and the largest spurious (harmonic) component in the output spectrum.…”

Efficient Wideband Channelizer for Software Radio Systems Using Modulated PR Filterbanks

“…This requires ADCs with spurious-free dynamic ranges (SFDRs) of 90-100 dB and sampling rates as high as 250 Msamples/s. Satisfying the computational requirements for fully channelizing or synthesizing such signals may demand the use of a large number of currently available DSPs for the SWR base station transceiver functionality [1]- [4].…”