Modulation and demodulation model based on SDMA According to multi-resolution analysis theory, the modulation and demodulation of signal c (t) is the process of wavelet reconstruction and decomposition. To this end, another function φ∈L2 (R) is introduced, and φmn (t) = 2m / 2φ ( 2mt-n), so that the two spaces based on ψ and φ are mutually orthogonal, then there are two sequences {p (n)} and {q (n)} such that Let fj and gj be functions on two orthogonal spaces Vj and Wj with scale j, respectively, then they have a unique series representation: From equations (8) and (9), the wavelet decomposition and reconstruction algorithm can be obtained In the case of limited resolution (ie m < Received signal SDMA modulation and demodulation model can be obtained by formula (10) ~ (12), as shown in Figure 1, 2. Figure 1 SDMA's multi-rate modulation model Figure 2 SDMA multi-rate demodulation (best receiver) model In actual systems, there are always Where Em is the average energy per symbol, and σ2 is the variance of AWGN. From equation (13), it can be seen that the bit error rate of each channel will be inconsistent. For Fire Extinguisher Use, Drop the auto fire extinguisher ball to extinguishing the fire. Fire Extinguisher Drone,Drone Fire Extinguisher,Forest Firefighting Drones,Drone For Fire Department Use shenzhen GC Electronics Co.,Ltd. , https://www.jmrdrone.com
(8a) 
(8b) 
(8c) 
(9a) 
(9b) 
(10a) 
(10b) 
(10c) ), Equation (4) can be rewritten as
(11) (t) = c (t) + n (t), n (t) is the channel noise, according to equation (11), the best receiver model can be obtained as
(12) 
, So the system capacity is M = -M,
And M are the upper and lower limits of the system resolution, respectively. If multi-level PAM modulation is used on a channel of scale m, the transmission rate of the channel is Bm = 2mlog2Lm bits / second, where Lm is the number of modulation levels. When the data is in
Transmission on the frequency band. For this modulation method, the bit error rate in the additive Gaussian fractal noise channel [2] can be obtained without coding. In fact, it is similar to the additive white Gaussian noise (AWGN) channel. 
(13)