A Low-Power Low-Complexity Multi-Standard Digital Receiver for Joint Clock Recovery and Carrier Frequency Offset Calibration

Efficient Integer Frequency Offset Estimation Architecture for Enhanced OFDM Synchronization

“…2(b), where N=256 for IEEE 802. 16. To significantly reduce buffer requirements, we delay computation of the IFO by 12 symbols, so that the compensation shift is always positive: S IFO = {0 : 4 : 28}.…”

“…12 is optimised for QPSK modulated pilots (since their amplitudes are identical) as specified in IEEE 802. 16, as well as in most OFDM-based standards. The normalisation performed in (7) allows the correlation to be reduced to two DSP blocks operating as 3-input adders (instead of 4 DSP blocks with multipliers as would be usual).…”

“…This can be achieved in practice through very strict and potentially expensive constraints on the RF front-end design, and avoiding application that significantly increase CFO, including mobility (i.e. Dopplerinduced CFO [4]) and cognitive radio (switching between multiple frequency bands leads to CFO [15], [16]). Like many recent works [17], [18], [19], this paper is concerned with IFO estimation, either to support large-CFO application scenarios, or to enable cost saving through relaxing strict front-end design criteria.…”