If we assume that [alpha], [beta], [gamma] and [delta] are coefficients which determine the distribution of the selected modulation formats (BPSK
, QPSK, 8QAM and 16QAM) in the network respectively, [alpha][greater than or equal to]0, [beta][greater than or equal to]0, [gamma][greater than or equal to]0, [delta][greater than or equal to]0 and [alpha]+[beta]+[gamma]+[delta]=1.
The new contents of the CSRR is fed serially bit by bit to the Binary Phase Shift Keying (BPSK
(14) to determine the estimated number of channels to be finely sensed by the cognitive radio, where the most conservative modulation scheme (i.e., BPSK
) is assumed in the transmission.
SUs operating in white hole II use 16 subcarriers, in IV use 32, in VI use 64, and in VIII use 128, each modulated with BPSK
. Figures 10 and 11 show that the proposed techniques are effective and reliable in such a spectrum sharing scenario and get significant reduction of sidelobes in comparison with the current techniques including CC using GA and DE , ASW , ACC , CC [7, 8], and GSC .
(3) Assuring generality, constellations BPSK
, QPSK, 8PSK, and 16QAM are assigned to each symbol in vector s, respectively.
PARAMETERS USED IN SIMULATIONS Parameters Values Modulations BPSK
Number of Symbols 100 Number of Subcarriers 64 Input Data Block Size 52 Block Oversampling 10 Roll-off factor, a 0.22 TABLE IV.
Hence, in the region r1, 16PSK, in r2, 8PSK, in r3, QPSK and in r4, BPSK
are to be used.
, QPSK, 8-PSK Demodulator for FPGA 5 pages," http://www.innovative-dsp.com/support/datasheets/IPPSK_DEMOD4.pdf.
The RF signal transmitted from earth is created by linear phase modulation of a 2.025 to 2.110 GHz carrier with a 16 kHz subcarrier, which is in turn BPSK
modulated by the 4 kbps data signal.
WRAN mainly uses the constellation points of BPSK
, QPSK, 16QAM, and 64QAM.