The Application And Implementation Of Digital Re-sampling In All-digital Receiver

The symbol synchronization for all-digital receiver is achieved by sampling theinput intermediate frequency (IF) signal in fixed sampling frequency, and then adjustingthe sampling rate using the synchronization loop with digital re-sampler in base band.This proposed symbol synchronization loop is universal and all-digital, and itovercomes many disadvantages of the conventional hybrid analog/digital structure. Inaddition, it is more suitable to deal with the signal with variable data rate.The theoretical model of the digital re-sampler shows that the design of impulseresponse of the interpolation filter and its control is the main issue to resolve. This paperspecially analyzes the principle and steps of the basis-function piecewise constructionmethod based on ploy-phase decomposition. And it concretely introduces how to selectthe piecewise interval, the domain to compute the weighted coefficients and the restraintconditions for optimization. The performance of this proposed method relative to theconventional method is improved, and it advantage is that its realization structure iseasy and the parameters are flexible to design according to the input signal spectrum.The last part of this paper is the simulation of the baseband transmission systemwith symbol synchronization loop using digital re-sampler. The experiment shows thatthe capture scale, anti-interfere and anti-noise performance of the loop can satisfyengineer requirements, and the bit-error performance of the above system is close to thesynchronously sampling baseband transmission system.