PROJECT TITLE :

Design and EXIT Chart Analysis of a Doubly Iterative Receiver for Mitigating Impulsive Interference in OFDM Systems

ABSTRACT:

During this paper, a doubly iterative receiver for orthogonal frequency-division multiplexing (OFDM) systems is intended to mitigate impulsive interference based mostly on pulse blanking. Although being a very economical countermeasure, pulse blanking introduces intercarrier interference in OFDM systems resulting in system performance degradation. The doubly iterative receiver is intended to overcome this disadvantage. The inner loop combines iterative demodulation and decoding to cancel intercarrier interference. To form soft info accessible to the outer loop, the equivalent noise power comes to employ soft demodulation. The outer loop improves the performance of pulse blanking by performing a hypothesis take a look at, which is employed to decide if peaks in the received signal are due to impulsive interference or the massive peak-to-average-power ratio common to OFDM signals. This allows to optimize the blanking threshold through maximizing the signal-to-interference-and-noise ratio. To judge performance and complexity of the proposed receiver, extrinsic data transfer (EXIT) chart analysis is distributed, where EXIT functions for pulse blanker, demodulator, and decoder are derived. An EXIT chart-based trellis search approach is introduced to calculate the loop schedule achieving target bit-error-rate performance with minimized complexity. Numerical results show a substantial bit-error-rate performance improvement as well as a exceptional complexity reduction.