Browsing by Subject "Pruning"

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • Thumbnail Image
    ItemOpen Access
    A tree pruning technique for decoding complexity reduction of polar codes and PAC codes
    (Institute of Electrical and Electronics Engineers , 2023-05-18) Moradi, Mohsen; Mozammel, Amir
    Sorting operation is one of the main bottlenecks for the successive-cancellation list (SCL) decoding. This paper introduces an improvement to the SCL decoding for polar and pre-transformed polar codes that reduces the number of sorting operations without visible degradation in the code’s error correction performance. In an SCL decoding with an optimum metric function we show that, on average, the correct branch’s bit-metric value must be equal to the bit-channel capacity, and on the other hand, the average bit-metric value of a wrong branch can be at most zero. This implies that a wrong path’s partial path metric value deviates from the bit-channel capacity’s partial summation. For relatively reliable bit-channels, the bit metric for a wrong branch becomes very large negative number, which enables us to detect and prune such paths. We prove that, for a threshold lower than the bit-channel cutoff rate, the probability of pruning the correct path decreases exponentially by the given threshold. Based on these findings, we presented a pruning technique, and the experimental results demonstrate a substantial decrease in the amount of sorting procedures required for SCL decoding. In the stack algorithm, a similar technique is used to significantly reduce the average number of paths in the stack.
  • Thumbnail Image
    ItemOpen Access
  • Thumbnail Image
    ItemOpen Access
    New Keynesian small open economy: Turkish case
    (2016-06) Ersoy, Sedat
    Turkey experienced substantial declines in inflation after 2002. Was it due to good policy, good luck, or both? To address this question, we incorporate stochastic volatility into a small open new Keynesian model of Monacelli (2005). As demonstrated by Fernandez-Villaverde, Guerron-Quintana, Rubio-Ramirez (2010), volatility shocks are an importance source of macroeconomic fluctuations so they need to be accounted for in order to examine the good luck hypothesis rigorously. Our estimated model suggests that both good policy and good luck played roles in bringing down the inflation.