The obtained results indicate that free run oscillator phase noise characterization is not appropriate when the Local Oscillator in the radio-frequency front end is based on synthesizer architecture.
Another important hardware choice concerns the radio frequency front end circuit.
Hackberry board connected to the SiGe radio frequency front end (right panel).
In radio frequency front end, the efficiency of HPA is degenerated with increasing PAPR of input signals [11 13].
Furthermore, the radio frequency front end of the user terminal needs to be tuneable and configurable to operate at a particular frequency band depending on shareable spectrum availability for its operator to support different spectrum of operation.
This system was basically composed of an antenna, a plastic-wood support where the receiving antenna was fixed in order to maintain a specific height from the terrain, a radio frequency front end circuit for the frequency down-conversion of the received signal and for its digital conversion, and a suitable hardware device to store and process the data (see Figure 1).
This variable is provided for the entire duration of one GPS C/A code period (1 ms) with a time resolution provided by the sampling rate of the radio frequency front end (which is 8.1838 MHz, i.e., 0.125 C/A code chip length being the entire code formed by 1,024 chips).
Each of the solutions offers different radio frequency front-end flexibility, sensing speed and accuracy and varies in the way the samples are processed and stored.
We show that the proposed transceiver is fast enough to exploit the channel reciprocity within the channel coherence time, from the medium perspective, i.e., from the transmitter's antenna (after the radio frequency front-end) to the receiver's antenna (before the radio frequency front-end).
Two types of radio-frequency front-end imperfections, that is, carrier frequency offset and the inphase/quadrature (I/Q) imbalance are considered for orthogonal frequency division multiplexing (OFDM) communication systems.
