On the Impact of Finite Receiver Resolution in Fading Channels

In this paper, we will consider the impact of finite resolution in a receiver analog-digital converter on the performance of square, linearly modulated systems over fading channels. We show that in fading channels, the probability of error in a quantized system cannot be reduced to zero due to the introduction of quantization noise, even for arbitrarily large SNR. The error floor occurs due to a nonzero number of outage events events caused by channel fading below a threshold which does not decrease with SNR and is completely determined by quantization noise. We characterize this quantization noise and discuss the relation between number of receive antennas L, modulation order M , and bits of quantization b.