Subcarrier Power Allocation in OFDM With Low Precision ADC at Receiver
Orthogonal Frequency Division Multiplexing (OFDM) has been incorporated in standards/draft standards such as IEEE 80.15.3c, IEEE 802.11ad for building multi-Gigabit systems operating in a few GHz of bandwidth. The digital implementation of the receivers for such a system is challenging because high precision (6+ bits/sample) Analog-to-Digital Conversion (ADC) at such high speeds is power hungry and expensive. In this paper, the authors show that by suitable subcarrier power allocation they can get good performance even with low precision ADC (1-4 bits/sample without oversampling). They derive an analytical expression for the un-coded SER of an M-QAM OFDM system with finite precision ADC.