On the Impact of Fixed Point DSP Implementation on Required Channel Estimator Complexity in Communication Receivers

In this paper we discuss the impact that fixed point implementation of DSP units in a communication system chain has on the required complexity of channel estimators. We have restricted our model to a flat-fading channel and linear FIR estimators, under the assumption that finite word length effects in the DSP operations in the communication chain can be modeled as additional additive noise. We have shown that a small increase in this noise can lead to a considerable increase in the required estimator complexity if a given NMSE performance for the channel estimation must be upheld, in particular at medium- to-high CSNRs.