Hussein, Shirin;
(2023)
Transmission of Radio Frequency MIMO Signals over Fibre Using Digitisation and Digital Signal Processing Techniques.
Doctoral thesis (Ph.D), UCL (University College London).
Abstract
The challenges of transmitting radio multiple-input-multiple-output (MIMO) signals over a single optical fibre are that they all have the same carrier frequency and would overlap in the frequency domain. Previously, the phase quadrature double sideband (DSB) and single sideband frequency translation (SSB) techniques were proposed and demonstrated to frequency shift the MIMO signals before and after the fibre transmission so that a single optical fibre can be used to carry multiple MIMO signals even without employing wavelength division multiplexing (WDM). These two techniques are purely analogue and require exact frequency precision with custom-made microwave filters or diplexers. In this thesis, a novel digital technique based on converting the MIMO signals between the analogue and digital domains is proposed and demonstrated. Linear and nonlinear digital signal processing (DSP) are used to perform signal filtering and distortion compensation, respectively. Being able to compensate for the nonlinear distortion caused by, for example, a Mach- Zehnder modulator (MZM), is an added capability not found in the previous two analogue techniques. This thesis presents the experimental arrangements of digital DSB and SSB frequency translation techniques for translation of radio frequency (RF) MIMO signals over fiber using a field programmable gate array (FPGA). Using the proposed technique, three 10 MSymb/s 16-QAM MIMO channels of the same 2.4 GHz centre frequency were first digitised with three analogue-to-digital converters (ADCs). Two of the digitised MIMO signals were then frequency offset. The three digitised MIMO channels were then combined, pre-distorted and converted back to the physical analogue waveforms with a digitalto- analogue converters (DACs) and transmitted successfully over a single optical fiber with low error vector magnitude (EVM).
| Type: | Thesis (Doctoral) |
|---|---|
| Qualification: | Ph.D |
| Title: | Transmission of Radio Frequency MIMO Signals over Fibre Using Digitisation and Digital Signal Processing Techniques |
| Language: | English |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Electronic and Electrical Eng |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10172424 |
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