Explaining USRP integration #90

docs/telecommands_transmissions.rst

@@ -9,27 +9,66 @@ The Spacelab-Transmitter is the software for the Spacelab's Ground Station (GRS)
 
 In order to not depend on another software to transmit telecommands, it was implemented a GMSK modulator in the code so that the Spacelab Transmitter works alone with the Software-Defined Radio.
 
-The default Software-Defined Radio used in Spacelab is the USRP210 so the code was written based in the integration with this specific SDR.
+The default Software-Defined Radio used in Spacelab is the USRP B210 so the code was written based in the integration with this specific SDR.
 
 .. image:: img/usrp.png
    :width: 500
 
 GMSK Implementation
 ===================
 
+explain what is gmsk, how it works 
+
+explain our code: it was based in code .... of the book ....
+
 
 
 Integration with USRP SDR
 =========================
 
+Software-Defined Radio
+**********************
 
-References
-==========
-https://github.com/skagmo/ngham
+The IEEE considers Software defined to be refered to the use of software processing within the radio
+system or device to implement operating (but not control) functions and Software-Defined Radio (SDR) a radio in which some or all of the physical layer functions are software
+defined. [1]_ 
+
+As said before,the SDR used in Spacelab transmissions to satellites is the USRP B210.
+
+USRP
+****
+
+Means Universal Software Radio Peripheral, it's a family os SDRs designed by the Ettus Research and NI. The B210 has a continuous frequency coverage from 70 MHz to 6 GHz [2]_, which covers the frequencies used by the Spacelab's satellites.
+
+USRP Integration 
+****************
 
-https://github.com/mgm8/pyngham
+The USRP hardware driver (UHD) is the driver provided to the USRP radios. Since the Spacelab Transmitter code is in Python, it's necessary to install UHD and Python API and test them [3]_.
 
-https://pysdr.org/content/usrp.html
+The folder has a specific file for usrp class, where it has a constructor function and the transmit function. To transmit it's necessary to have the:
+
+- samples;
+- duration;
+- center frequency;
+- sample rate;
+- gain.
+
+In the code:
+
+ ``samples = signal.resample_poly(samples, self._sample_rate, rate)``
+
+ ``if self._usrp.send_waveform(samples, dur, freq, self._sample_rate, [0], self._gain):``
+    ``return True``
+ ``else:``
+    ``return False``
+
+And the true/false return is for if it was successfull or not.
+
+References
+==========
 
 Viswanathan, Mathuranathan. Digital Modulations Using Python. 1st ed., vol. 1, Independently published, 2019.
 
+.. [1] IEEE Project 1900.1 - Standard Definitions and Concepts for Dynamic Spectrum Access: Terminology Relating to Emerging Wireless Networks, System Functionality, and Spectrum Management https://standards.ieee.org/develop/project/1900.1.html.
+.. [2] https://www.ettus.com/all-products/ub210-kit/
+.. [3] https://pysdr.org/content/usrp.html