| Autor: |
Ali Khan, M. Zafar, Qadeer, S. Abdul, Khan, M. Yusuf |
| Předmět: |
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| Zdroj: |
IEEE Signal Processing Letters; Dec2006, Vol. 13 Issue 12, p721-724, 4p, 1 Diagram, 1 Chart, 1 Graph |
| Abstrakt: |
A comb spectrum evaluation problem arises in the channel estimation of pilot symbol-assisted modulation (PSAM) systems and also in the (de)modulation of multichannel communication system based on orthogonal frequency division multiplexing (OFDM). In this letter, we decompose an M-component comb spectrum evaluation with transform length N into 1) a fast Fourier transform evaluation of transform length M of a length M vector, 2) which in turn is obtained from the length N input vector (by folding and scaling). This decomposition allows for the application of split-radix and radix-4 algorithms for evaluation of M length transform and efficient computation of the length M vector from the length N input vector, which is classically termed as "pruning." When N = 2p, the comb spectrum computation requires only N/ 8 + M/3 log2 M nontrivial complex multiplications, if N/M ≤ 8. In addition, conditions under which comb spectrum evaluation can be done in O(M log M) complex multiplies are identified. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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