The colored squares correspond to pilot symbols.
In our simulation, we set the number of data symbols 5. Since x=1 is assumed to be sent as a pilot symbol, the received signals corresponding to two pilot signals are expressed as: y_{i} t,l)=h_{i} t,l)+n_{i} t,l)+i_{i} t,l).,, i = 1, 2. (2) Figure 2 Packet structure.
Note that for each antenna transmitting an OFDM symbol with K s active subcarriers, only K p i and K d i are used for pilot and data transmission, while subcarriers corresponding to the pilot symbols of other transmit antennas are nulled.
Measurement matrix U Δ is a structured random matrix which is formed by selecting a row vector of unitary matrix corresponding to the pilot point.
Then, the beliefs of those subvectors of h rk, corresponding to the pilot indices (mathcal {P}), are computed successively for each k.
With the uniform positioning, the design of the synchronization waveform, that is obtained by considering the time domain signal corresponding to the pilot tones, is simple and easy to analyze.
Let h Δ = h l, k ∈ P, U Δ = U l, k ∈ P be the matrix corresponding to the pilot point, and z Δ be the set of z ~ l, k in l, k ∈ P. We have h Δ = U Δ g + z Δ (29).
At high altitudes, an Aviation Oxygen Supply System (AOSS) protects pilots from low pressure and hypoxia by continuously providing oxygen corresponding to the pilots' dynamic respiratory properties.
Figure 5 shows how to deal with pilot carriers in the message passing process, where s n and f k are the variable and function nodes corresponding to a given pilot symbol, respectively.
