Direct-conversion receiver (DCR) architecture has received considerable attention recently owing to its portable architecture and superior performance in terms of power and cost over its super-heterodyne counterpart. Flicker noise is one of the major impairments which severely affects the performance of the system. In this work, we investigate the use of signal processing techniques in the mitigation of flicker noise in OFDM-based systems which employ DCR architecture. The statistical properties of flicker noise are exploited to develop adaptive signal processing algorithms that reduce the effect of flicker noise in DCRs. Results indicate that signal processing algorithms can provide significant performance gain under low SNR conditions.