Electrical engineering

Channel (broadcasting)

MIMO

Quantization (signal processing)

Capacitor

Algorithm

Engineering

Telecommunications link

Voltage

Electronic engineering

Computer science

Rician fading

Fading

Decoding methods

Successive approximation ADC

Telecommunications

IEEE Communications Letters

In this letter, we introduce a mixed analog-todigital converter (ADC) receiver architecture to cell-free massive multi-input multi-output (mMIMO) system under Rician fading channels. In particular, the mixed-ADC architecture permits some of receiver's antennas to be implemented with economical low-resolution ADCs, while the rests are equipped with highpriced perfect ADCs. Leveraging on the additive quantization noise model (AQNM), a tight approximate uplink spectral efficiency (SE) expression with matched filtering receiver is derived, which provides us with a tool for easily quantifying the impacts of the Rician K-factor, the quantization bit of lowresolution ADCs, and the proportion of the perfect ADCs in the mixed-ADC architecture. Numerical observations demonstrate that the mixed-ADC architecture with a small fraction of perfect ADCs has a great potential to boost the SE compared to the case with pure low-resolution ADCs. Moreover, the mixed-ADC architecture is superior to the full perfect ADCs counterpart in terms of energy efficiency (EE).

On the Performance of Cell-Free Massive MIMO With Mixed-ADC Under Rician Fading Channels