From: Efficient blind spectrum sensing for cognitive radio networks based on compressed sensing
x(t) | A continuous-time signal with finite energy |
X(f) | The Fourier transform of x(t) |
x[n] | Bounded energy sequence |
v | Vector |
v i , or v(i) | i th entry of v |
v(f) | Vector that depends on a continuous parameter f |
Φ | Matrix |
Φ ik | ik th entry of Φ |
Φ i | i th column of Φ |
r t | Samples vector of a signal at time domain |
r f | Samples vector of a signal at frequency domain |
| Non-zero frequency-domain support |
q,L | q number of blocks and L denotes the number of all blocks |
B,B i | Bandwidth of sub-band, B i denotes the i-th sub-band |
Q | Threshold for blind spectrum reconstruction |
∥x∥0 | ℓ0-norm of x |
∥x∥ p | ℓ p -norm of x, which is defined as |
I(A) | Support of A |
| Denote a set of signals in CRN |