43 * Output frames are composed of 8 upchirps, 2 sync words (8 and 16), 2.25 downchirps and 'pay_len' symbols.
44 * The first frame is output after 'offset' samples and each frame after is spaced of 'delay' samples. If rand_sto is true, the sto will vary
45 * for each frame, with a value uniformly distributed in [0, os_factor*2^sf). Zeros are output between frames. If a file_sink is connected, the payload
46 * will be random for each frame and saved to the file selected. Else a fix payload defined in frame_src_impl.cc will be used.
47 *
48 * \param sf Spreading factor
49 * \param pay_len length of the payload in number of symbols
50 * \param delay number of samples between two frames
51 * \param offset number of samples before the first frame (used to emulate the sampling frequency offset).! The offset of the first user should be smaller than 2^'sf'*'os_factor'!
52 * \param cfo Carrier frequency offset
53 * \param n_frames Number of frames to send
54 * \param os_factor Oversampling factor
55 * \param rand_sto Indicate to use a random sto for each frame
56 */
57staticsptrmake(uint8_t sf, int pay_len, int delay, int offset, float cfo, int n_frames, int os_factor, bool rand_sto);