From: Optimized spectrum sensing algorithms for cognitive LTE femtocells
FWT | FFT |
---|---|
A single FWT operation per LTE OFDM symbol (5 slots × 7 FWT operations) | The five LTE slots are divided into FFT blocks according to the FFT size, the average FFT of these blocks is the output of the FFT sensing module |
Complexity = 2 × (Number of samples per LTE OFDM Symbol) × 7 × 5 × M × L | Complexity = (Number of FFT blocks per 5 LTE slots) × FFT_Size × log2(FFT_Size) |
Daubechies (dbN) wavelets are used where N is the filter order | 256 and 512 point FFT modules are used |
1598520 computations for db2 FWT 3197040 computations for db4 FWT | 1599488 computations for 256-point FFT 1797120 computations for 512-point FFT |