The distributions of the 4FSK, BPSK
, Frank, and Barker signals are more concentrated and have much narrower frequency bandwidths, meaning that they are compact-class distributions.
A frame consisting of LDPC coded bits is sent from the LDPC encoder with all the bits with random values 0 and 1 which has further been BPSK
modulated and broadcast to the relays.
Based on that, let [C.sub.WDM] be the channel capacity of BPSK
WDM, the number of spectrum slots needed in the conventional WDM network, [NS.sub.WDM] (s, d), can be calculated as,
Chip modulation may be any version of coherent modulations, such as BPSK
, QPSK, 8-PSK (Phase Shift Keying), but generally, binary phase shift keying (BPSK
) is employed.
[S.sub.BPSK]([absolute value of ([f.sub.w] - [f.sub.j])]) is the power spectrum in BPSK
modulation, [T.sub.f] is the symbol duration, [f.sub.i] is subcarrier frequency of node i.
SCPC method is similar to that of BPSK
, and this method destroys the narrow peak of autocorrelation function (ACF).
where D denotes the data length which is known by the source, and Rbpsk is the data transmission rate of BPSK
. The data transmission rate in the OFDMA system can be determined by the number of modulation symbols Ns, number of available sub-carriers k, and sample time [tau].
Different from BPSK
, the primary correlation peak of the BOC signal is more narrow than BPSK
Simulation conditions Simulation I Simulation II Transmitted signal p(k) BPSK BPSK
SNR 45 dB 45 dB Pulse magnitude 1 1 Pulse width 5000 2000 Dimension of the equalizer 16 x 2 = 32 16 x 2 = 32 [N.sub.f] Oversampling rate M 2 2 Step size 5 x [10.sup-3] 5 x [10.sup.-3] Table 4: Coefficients of the two channels.
SUs functioning in bands II, IV, VI, and VIII use 32 OFDM subcarriers, mapped with BPSK
. The performances of the proposed techniques in terms of PSD with others, including ASW , ACC , CC [7, 8], CC using GA and DE , and GSC , are shown in Figures 6 and 7.
This bitwise computation achieves acceptable accuracy for single-input single-output (SISO) and 2x2 MIMO channels with BPSK
, QPSK, 16QAM, and 64QAM .
A pair of BPSK
symbols is mapped to QPSK constellation with a phase difference of 90[degrees] and 180[degrees] in two different cases.