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Optoelectronic technology is expected to be the cornerstone of sub-THz communication systems, enabling access to and use of the vast frequency resources found in this portion of the spectrum. In this work we demonstrate a photonics-enabled sub-THz wireless link operating in real-time settings, using a PIN-PD-based THz emitter, and a THz receiver based on an ultra-fast photoconductor. The real-time generation and detection of the information signal is performed by an intermediate frequency (IF) unit based on a commercially available mmWave platform, operating at 1.6 GBaud. The evaluation of our setup takes place on two phases. Firstly, a homodyne scenario is demonstrated, where the same pair of lasers is used at the transmitter and receiver side. Secondly, we demonstrate a heterodyne scheme, employing optical phase locking techniques at the receiver. Error-free operation was achieved in both scenarios at a bit rate of 3.2 Gb/s, over 1 m of free-space with ambient air. The broadband characteristics of our setup were validated, achieving error-free transmission over a 0.22 THz range, spanning from 90 up to 310 GHz. Finally, the stability of our real-time link was successfully demonstrated, showing stable SNR performance at the receiver with adaptive capabilities, over a time period of 5 min and 22 sec.

This deliverable presents intermediate results of all the project demonstrators envisioned in ARIADNE. The two hardware demonstrators make use of all the development work of WP3, while the work outcomes of WP4 lead to the software demonstrators. The intermediate results presented here pave the way for the final deliverable D5.3

Photonic integrated circuits (PICs) are one of the key enablers for beyond 5G networks. A novel generation of fully integrated photonic-enabled transceivers operating seamlessly in W- D- and THz-bands is developed within the EU funded project TERAWAY. Photonic integration technology enables key photonic functionalities on a single PIC including photonic up/down conversion. For efficient down-conversion at the photonic integrated receiver, we develop the first waveguide-fed photoconductive antenna for THz communications. Finally, we report on the experimental implementation of a fully photonic-enabled link operating across W- D- and THz-bands.

[EN] The sixth generation (6G) mobile systems will create new markets, services, and industries making possible a plethora of new opportunities and solutions. Commercially successful rollouts will involve scaling enabling technologies, such as cloud radio access networks, virtualization, and artificial intelligence. This paper addresses the principal technologies in the transition towards next generation mobile networks. The convergence of 6G key-performance indicators along with evaluation methodologies and use cases are also addressed. Free-space optics, Terahertz systems, photonic integrated circuits, softwarization, massive multiple-input multiple-output signaling, and multi-core fibers, are among the technologies identified and discussed. Finally, some of these technologies are showcased in an experimental demonstration of a mobile fronthaul system based on millimeter 5G NR OFDM signaling compliant with 3GPP Rel. 15. The signals are generated by a bespoke 5G baseband unit and transmitted through both a 10 km prototype multi-core fiber and 4 m wireless V-band link using a pair of directional 60 GHz antennas with 10 degrees beamwidth. Results shown that the 5G and beyond fronthaul system can successfully transmit signals with both wide bandwidth (up to 800 MHz) and fully centralized signal processing. As a result, this system can support large capacity and accommodate several simultaneous users as a key candidate for next generation mobile networks. Thus, these technologies will be needed for fully integrated, heterogeneous solutions to benefit from hardware commoditization and softwarization. They will ensure the ultimate user experience, while also anticipating the quality-of-service demands that future applications and services will put on 6G networks., This work was partially funded by the blueSPACE and 5G-PHOS 5G-PPP phase 2 projects, which have received funding from the European Union's Horizon 2020 programme under Grant Agreements Number 762055 and 761989. D. PerezGalacho acknowledges the funding of the Spanish Science Ministry through the Juan de la Cierva programme.

This article presents an experimental demonstration of a high-capacity millimeter-wave 5G NR signal transmission with analog radio-over-fiber (ARoF) fronthaul over multi-core fiber and full real-time processing. The demonstration validates the core of the blueSPACE fronthaul architecture which combines ARoF fronthaul with space division multiplexing in the optical distribution network to alleviate the fronthaul capacity bottleneck and maintain a centralized radio access network with fully centralized signal processing. The introduction of optical beamforming in the blueSPACE architecture brings true multi-beam transmission and enables full spatial control over the RF signal. The proposed ARoF architecture features a transmitter that generates the ARoF signal and an optical signal carrying a reference local oscillator employed for downconversion at the remote unit from a single RF reference at the central office. A space division multiplexing based radio access network with multi-core fibre allows parallel transport of the uplink ARoF signal and reference local oscillator at the same wavelength over separate cores. A complete description of the real-time signal processing and experimental setup is provided and system performance is evaluated. Transmission of an 800 MHz wide extended 5G NR fronthaul signal over a 7-core fibre is shown with full real-time signal processing, achieving 1.4 Gbit/s with a bit error rate $$ < 3.8 × 10 - 3 and thus below the limit for hard-decision forward error correction with 7% overhead.

In 5G networks, a Radio over Fiber architecture utilizing multicore fibers can be adopted for the transmission of mmwave signals feeding phased array antennas. The mmwave signals undergo phase shifts imposed by optical true time delay networks, to provide squint free beams. Multicore fibers are used to transfer the phase shifted optical signals. However, the inter-core static skew of these fibers, if not compensated, distorts the radiation pattern. We propose an efficient method to compensate the differential delays, without full equalization of the transmission path lengths, reducing the power loss and complexity. Statistical analysis shows that regardless of the skew distribution, the frequency response can be estimated with respect to the rms skew delays. Simulation analysis of the complete Radio over Fiber and RF link validates the method.

A tunable high-resolution synthesizer based on optoelectronic phase locked loop is proposed for the generation of microwave and mmWave frequencies. Optical modulation, frequency division, and phase locking processes are deployed to generate a tunable lower frequency exhibiting suppressed phase noise. Moreover, a dense tunable optical comb locked to the widely spaced reference is produced. A suite of microwave and mmWave frequencies in multiple frequency bands emerges from the beating of the generated optical frequency components and optical or electrical filtering may isolate the frequency bands of interest. The phase noise of the synthesized frequencies depends on the optical power of the input reference comb. The experimental evaluation, including Allan deviation and phase noise measurements, prove the high stability performance of the proposed scheme.

This paper presents an experimental demonstration of analog radio-over-fiber (ARoF) fronthaul for high-bandwidth, high-capacity millimeter wave (mm-wave) extended fifth generation mobile network (5G) new radio (NR) signals over an optical distribution network with optical space division multiplexing (SDM). ARoF is shown to alleviate fronthaul capacity bottlenecks, transporting an 800 MHz wide extended 5G NR signal and allowing to maintain full centralization in a centralized radio access network (C-RAN). The proposed ARoF fronthaul architecture features a transmitter that generates the ARoF signal and an optical signal carrying a reference local oscillator (LO) employed for downconversion at the remote unit (RU) from a single radio frequency (RF) reference at the central office (CO). An SDM based RAN with 7-core multi-core fiber (MCF) allows parallel transport of the uplink ARoF signal and reference LO at the same wavelength over separate cores. Transmission of an 800 MHz wide extended 5G NR fronthaul signal over 7-core MCF is shown with full real-time processing, achieving 1.4 Gbit/s with BER

The blueSPACE project focuses on the study of innovative technologies to overcome the limitations of current fronthaul networks. The key technology proposed is space-division multiplexing, which makes it possible to increase the capacity available in conventional single-mode fibers, effectively encompassing this capacity to the forecasted bandwidth demands imposed by 5G mobile communications. In this paper, we present the innovative optical fronthaul infrastructure proposed in the project and the tailored extensions to the European Telecommunications Standards Institute network function virtualization management and orchestration architecture for this enhanced infrastructure together with practical implementation considerations.

The introduction of millimeter wave (mm-wave) frequency bands for cellular communications with significantly larger bandwidths compared to their sub-6 GHz counterparts, the resulting densification of network deployments and the introduction of antenna arrays with beamforming result in major increases in fronthaul capacity required for 5G networks. As a result, a radical re-design of the radio access network is required since traditional fronthaul technologies are not scaleable. In this article the use of analog radio-over-fiber (ARoF) is proposed and demonstrated as a viable alternative which, combined with space division multiplexing in the optical distribution network as well as photonic integration of the required transceivers, shows a path to a scaleable fronthaul solution for 5G. The trade-off between digitized and analog fronthaul is discussed and the ARoF architecture proposed by blueSPACE is introduced. Two options for the generation of ARoF two-tone signals for mm-wave generation via optical heterodyning are discussed in detail, including designs for the implementation in photonic integrated circuits as well as measurements of their phase noise performance. The proposed photonic integrated circuit designs include the use of both InP and SiN platforms for ARoF signal generation and optical beamforming respectively, proposing a joint design that allows for true multi-beam transmission from a single antenna array. Phase noise measurements based on laboratory implementations of ARoF generation based on a Mach–Zehnder modulator with suppressed carrier and with an optical phase-locked loop are presented and the suitability of these transmitters is evaluated though phase noise simulations. Finally, the viability of the proposed ARoF fronthaul architecture for the transport of high-bandwidth mm-wave 5G signals is proven with the successful implementation of a real-time transmission link based on an ARoF baseband unit with full real-time processing of extended 5G new radio signals with 800 MHz bandwidth, achieving transmission over 10 km of 7-core single-mode multi-core fiber and 9 m mm-wave wireless at 25.5 GHz with bit error rates below the limit for a 7% overhead hard decision forward error correction.

The fundamental properties of free space optical channels in the ultraviolet (UV) spectral range between 200 and 280 nm are the enhanced scattering and the solar blind operation. Exploiting these properties, point-to-point links in a non-line-of-sight (NLOS) regime were experimentally tested and the performance of pulse position modulation of fourth order (4-PPM) and flip–orthogonal frequency division multiplexing (Flip-OFDM) modulation formats was evaluated. At the transmitting side, light-emitting diodes (LEDs) emitting at 265 nm were used. At the receiving side, a photo-multiplier tube was combined with an optical filter. Distances up to 20 m were covered and kilobits/s rates were applied. The performance was also evaluated after modifying artificially the atmospheric conditions by the operation of a fog machine. In short, 4-PPM outperformed Flip-OFDM, whereas a medium that offers enriched scattering due to fog may boost the performance of short-range NLOS links in the UV spectral range.

Part 2: Poster Papers; International audience; Multicore fibers can be used for Radio over Fiber transmission of mmwave signals for phased array antennas in 5G networks. The inter-core skew of these fibers distorts the radiation pattern and has to be measured and compensated. We propose a method to accurately measure the differential delays remotely, after installation, without intervening heavily with the transmitter setup. The properties of the phase response measured at a distant receiver are exploited to acquire the differential delays among the antenna array elements.

Optically coupled semiconductor lasers (SLs) are known to exhibit chaotic properties in their emitted signals. Depending on the number of SLs and the coupling topology, their emissions can potentially show stable, synchronized behavior. The level of synchrony depends on numerous parameters and is the key factor to design secure communication systems based on synchronized chaotic signals. In this work we investigate a bidirectional coupling topology, with two or more SLs coupled with a common hub SL, which leads to an unprecedented level of synchronization. Cross-correlation (CC) values as high as 0.9961 are reported between SLs, when the latter operate at a fully chaotic regime and with spectral emission profiles that show minimized periodicities. Such conditions promote the proposed topology for cryptographic applications.

This paper presents a novel multi-level phase quantizer with the potential of almost ideal step like transfer function. Its operation relies on the proper combination of phase sensitive amplification in highly nonlinear fibers and amplitude limitation offered by injection locked lasers. Thorough investigation of the quantization properties of the scheme is theoretically and numerically conducted under ideal and non-ideal operating conditions. The properties of the limiter and their impact on the quantization performance are highlighted. The regenerative operation is demonstrated numerically by showing that a regenerated differentially decoded quaternary shifted keyed signal exhibits almost identical bit error rate performance with homodyne detection.

A framework for investigating the effects of different LiFi modulation techniques on the emitted light quality of an LEDs is presented. It is a valuable tool for designing LiFi systems that are compliant with lighting and data communication requirements.

A tunable synthesizer based on optoelectronic phase locked loop is proposed, for the generation of microwave and mmwave frequencies using optical modulation, frequency division and phase locking processes. The synthesizer maintains the fractional stability of the optical comb reference.

The concept of hybrid polymer optical fibre (POF) and visible light communication (VLC) for in-home networking is experimentally evaluated in this paper. The performance evaluation is based on two schemes of discrete multitone (DMT) and multilevel pulse amplitude modulation (PAM) techniques. The combined effects of modal dispersion of the POF and the limited bandwidth of the phosphor converted illumination LEDs induced frequency selectivity in the heterogeneous link. Equalisers are subsequently used to ameliorate the frequency selectivity of the channel. Results show that from a limited link 3-dB bandwidth of 17 MHz, a data rate of 122 Mbps is attainable using DMT with bit-loading while 91 Mbps is achievable with the low complexity PAM-4. The experimental demonstration results presented in this paper show that the POF/VLC hybrid represents a viable concept to extend the optical bandwidth available in the access network to the in-home network.

In this letter, rate-adaptive bit-loading techniques are explored for maximizing the transmission rate of spreading multicarrier modulation schemes over step index plastic optical fiber (SI-POF) short range transmission links. Both the discrete Fourier transform (DFT)-spread discrete multitone (DMT) and code division multiple access-DMT are experimentally evaluated and compared against conventional rate adaptive DMT, over a 50-m intensity modulation direct-detection (IM/DD) link of 1-mm PMMA SI-POF. It is shown that both schemes achieve better performance than DMT, whereas DFT-spread DMT behaves best among them, over the same experimental setup.

In this letter, the code division multiple access discrete multitone (CDMA-DMT) modulation scheme is experimentally investigated for transmission over an intensity modulation direct-detection link of 100 m of 1-mm polymethyl methacrylate step-index plastic optical fibers. CDMA-DMT is a multicarrier modulation scheme combining the merits of both CDMA and DMT and in which CDMA is utilized to perform a spreading operation of the data symbols in the frequency domain using orthogonal spreading codes. It is experimentally shown that CDMA-DMT performs better than conventional DMT in terms of achieved bit-error rate, for transmission rates in the range of 1 Gbps and over the same experimental configuration.

For several years, it has been examined if the attributes of the wavelengths in C band of the Ultraviolet (UV) spectrum that lie between 200 and 280 nm can be exploited in order to set up short range covert links of low rate in a Non-Line-of-Sight (NLOS) regime. In the present work, it is experimentally investigated and verified that using this band, short range and low rate NLOS links using the same transmitter/receiver pair under different atmospheric conditions without applying extreme power levels can be implemented rather effectively. The transmitter was composed of four Light Emitting Diodes. At the receiving side, an optical filter was followed by a Photo-Multiplier Tube. Initially, we measured the power losses of the channels with and without fog (artificially generated) for ranges up to 20 meters and several transmitters/receiver configurations. Secondly, the performance of Fourth-order Pulse Position Modulation (4-PPM) and Flip Orthogonal Frequency Division Multiplexing (Flip-OFDM) was evaluated for such channels and 10 Kbit/s rate. Applying emissions at 265 nm, NLOS links can operate efficiently especially in harsh environments, as the power losses were lowered when fog appeared. In terms of the modulation formats, 4-PPM performed better in most cases. Better results were obtained for both schemes when the medium became thicker due to the presence of fog. Finally, some initial measurements were realized with a Silicon Carbide PiN photodiode for the same rate but low elevation angles. The performance was exactly the opposite compared to a receiver with inherent gain when the atmosphere thickened.

The exploitation of optical wireless communication channels in a non-line-of-sight regime is studied for point-to-point and networking configurations considering the use of light-emitting diodes. Two environments with different scattering center densities are considered, assuming operation at 265 nm. The bit error rate performance of both pulsed and multicarrier modulation schemes is examined, using numerical approaches. In the networking scenario, a central node only receives data, one node transmits useful data, and the rest of them act as interferers. The performance of the desirable node's transmissions is evaluated. The access to the medium is controlled by a code division multiple access scheme.

We present the effect of LiFi, with on-off keying modulation technique, on the quality of light emitted from LEDs. Findings show that to preserve the LED light quality, the LiFi data signal should be such that the LED average drive current remains unchanged.

Over the recent years many modulation schemes were proposed for laser based high-speed short-range transmission over step-index plastic optical fiber (SI-POF). Among these schemes, CAP and DFT-Spread DMT demonstrated a good performance for intensity modulation direct-detection transmission via SI-POF. In this work, for the first time, we report on the progress and initial experimentation regarding the comparison of CAP and DFT-Spread DMT for transmission over 50m of 1-mm SI-POF. It is shown that CAP and DFT-Spread DMT achieve a comparable transmission rate for a given bit error rate over the same experimental configuration.

Semiconductor lasers (SL) have been proven to be a key device in the generation of ultrafast true random bit streams. Their potential to emit chaotic signals under conditions with desirable statistics, establish them as a low cost solution to cover various needs, from large volume key generation to real-time encrypted communications. Usually, only undemanding post-processing is needed to convert the acquired analog timeseries to digital sequences that pass all established tests of randomness. A novel architecture that can generate and exploit these true random sequences is through a fiber network in which the nodes are semiconductor lasers that are coupled and synchronized to central hub laser. In this work we show experimentally that laser nodes in such a star network topology can synchronize with each other through complex broadband signals that are the seed to true random bit sequences (TRBS) generated at several Gb/s. The potential for each node to access real-time generated and synchronized with the rest of the nodes random bit streams, through the fiber optic network, allows to implement an one-time-pad encryption protocol that mixes the synchronized true random bit sequence with real data at Gb/s rates. Forward-error correction methods are used to reduce the errors in the TRBS and the final error rate at the data decoding level. An appropriate selection in the sampling methodology and properties, as well as in the physical properties of the chaotic seed signal through which network locks in synchronization, allows an error free performance.

Ultrafast physical random bit generators based on broadband optical signals have been presented lately at astounding speeds. Some of the most popular mechanisms to obtain such random sequences are through signals that emerge from the coherence collapse operation of semiconductor lasers or from the photodetection signal beating of amplified spontaneous emission optical noise. Especially in the first case, the potential of chaotic signals to synchronize offers a great potential for secure communications. In this paper, we combine two unique properties of semiconductor lasers that operate at a chaotic regime: Their potential to become highly synchronized when optically coupled through appropriate configurations and their ability to seed ultrafast true random bit generators. The concurrent fulfillment of both conditions is shown in this paper and is used to demonstrate experimentally the one-time-pad encryption communication protocol. We report an error-free operation of such an encryption system, exceeding for the first time the Gb/s rate. Forward-error-correction coding is applied on the encryption scheme, in order to drastically reduce the errors of the synchronized true random bit sequences and optimize the decoding performance of the system, while securing the distribution of the random seed., The current work was supported by Greek General Secretariat for Research and Technology under the funding research action "ARISTEIA II" and the project "CONECT-4750" and was performed at the Department of Informatics and Telecommunications, National and Kapodistrian University of Athens, Panepistimiopolis, Ilisia, 15784, Greece.

The most common optical amplified spontaneous emission sources can become the ultimate tools for the generation of ultra-broadband truly random bit sequences (TRBS). By using a straightforward configuration we experimentally prove that the amplified spontaneous emission noise of an optical amplifier-either an Er+3 -doped fiber amplifier (EDFA) or an InGaAs semiconductor optical amplifier (SOA)-is an efficient source for TRBS generation. A bit rate up to 560 Gb/s has been recorded, seeded by the direct detection of the unfiltered spontaneous-spontaneous (sp-sp) optical intensity beat noise on a broadband photoreceiver. The generation rate is practically limited only by the detection bandwidth, the electronic digitization process and the post-processing circuitry. The proposed mechanism passes the existing benchmarks of randomness.

The increasing demand for high data rates in wireless networks indicates radio-over-fiber (RoF) as an excellent candidate for physical layer infrastructure in the development of future broadband communication systems. In this work, a thorough investigation on the performance of an intensity-modulation direct detection (IM-DD) RoF system utilizing orthogonal frequency division multiplexing (OFDM) is performed, emphasizing on the transmitter's impairments, and to what extend the above limitations are compensated by typical demodulation techniques implied in OFDM technology. It is shown that an acceptable performance is depicted up to 5.8 GHz carrier frequency, by a proper adjustment of the laser's current RF amplitude level.

In this paper we describe the design and deployment of a real-time simplex wireless SISO- and MISO-OFDM transmission setup on 5GHz employing two TMS320C6713 DSP Starter Kits (DSKs) as the baseband transmitter and receiver. The baseband system level design is done using Matlab/Simulink and the deployment on the TMS320C6713 DSKs is performed by means of IDE link via automatic code generation directly from Simulink blocks, offering a flexible way from system level design and simulation to actual implementation and verification. The wireless part is built based on conventional components and employs two transmit and one receive antennas. For both SISO and MISO, all the basic building blocks are comprised also including Maximum Likelihood (ML) synchronization based on the cyclic prefix as well as sampling clock frequency offset estimation and compensation. The implemented test-bed is intended primarily for educational demonstration and experimentation purposes for highlighting and studying several concepts and phenomena not only regarding the modulation schemes but the wireless link as a whole. Typical results for the experimental demonstration and evaluation of the system are presented.

One of the most critical parameters in free-space optical communications systems operating in a non-line-of-sight regime are the optical losses. In this Letter, we numerically calculate these losses taking into account the scattering effects using the Monte Carlo simulation technique. The obtained results are compared with experimentally obtained data at 265 nm (solar-blind UV regime). A large set of measurements at distances up to 20 m, for different elevation angles of the transmitter (UV-LEDs) and receiver (photomultiplier tube) and for different atmospheric conditions has been taken for the characterization of the optical communications channel in terms of its loss properties.

In this paper we describe the design and implementation of real-time wireless transceivers for advanced multicarrier modulation schemes, namely OFDM, SC-FDMA and MC-CDMA. The baseband system level design is done using Matlab/Simulink and the implementation is done using the TMS320C6713 DSK from Texas Instruments Inc. Cooperation of Matlab IDE and Code Composer Studio IDE allow for automatic code generation directly from Simulink blocks, offering a flexible way from system level design and simulation to actual implementation and verification. The wireless (RF) part is based on conventional components. For all multicarrier schemes we explore most of the basic building blocks that constitute them. The implemented testbed is intended primarily for educational demonstration and experimentation purposes offering the means for highlighting and studying several concepts and phenomena regarding not only the modulation schemes but the wireless link as a whole. Typical results concerning the experimental demonstration, evaluation and verification of the testbed are presented.

In this letter, the discrete Fourier transform-spread discrete multitone modulation (DFT-spread DMT) scheme has been used for the first time in laser-based short range optical transmission (over 100 m) with 1-mm step-index plastic optical fiber link, and its superior performance, compared with the standard DMT scheme, was demonstrated. The DFT-spread DMT combines the advantages of both single carrier and multicarrier transmission together with a lower peak-to-average power ratio. Under the same experimental conditions, a lower bit-error-rate is achieved with DFT-spread DMT compared with standard DMT for transmission rates in the 1-Gb/s range.

The performance of Space-Time Block Codes combined with Discrete MultiTone modulation applied in a Large Core Step-Index POF link is examined theoretically. A comparative study is performed considering several schemes that employ multiple transmitters/receivers and a fiber span of 100 m. The performance enhancement of the higher diversity order configurations is revealed by application of a Margin Adaptive Bit Loading technique that employs Chow's algorithm. Simulations results of the above schemes, in terms of Bit Error Rate as a function of the received Signal to Noise Ratio, are provided. An improvement of more than 6 dB for the required electrical SNR is observed for a 3 × 1 configuration, in order to achieve a 10(-3) BER value, as compared to a conventional Single Input Single output scheme.

In this paper, semiconductor microring lasers with integrated phase sections in the bus waveguide are numerically evaluated, using a dynamic multimode laser model, and investigated as low-cost, integrated, potential tunable directly modulated transmitters for future hybrid optical–wireless networks. The effect of optical feedback through bus waveguide is revealed as a promising mechanism for improving nonlinear distortion. Additionally, tunability is achieved with the aid of phase-tuning. The underlying laser dynamics beyond this behavior are analyzed.

Broadband chaotic signals generated by a photonic integrated circuit are employed to provide true random bit streams at Gb/s rates. Chaotic waveforms with appropriate spectral distribution and statistics succeed, after sampling, to pass randomness tests specified by NIST organization.

In the present work a photonic integrated circuit (PIC) that emits broadband chaotic signals is employed for ultra-fast generation of true random bit sequences. Chaotic dynamics emerge from a DFB laser, accompanied by a monolithic integrated 1-cm long external cavity (EC) that provides controllable optical feedback. The short length minimizes the existence of external cavity modes, so flattened broadband spectra with minimized intrinsic periodicities can emerge. After sampling and quantization--without including optical de-correlation techniques and using most significant bits (MSB) elimination post-processing--truly random bit streams with bit-rates as high as 140 Gb/s can be generated. Finally, the extreme robustness of the random bit generator for adaptive bit-rate operation and for various operating conditions of the PIC is demonstrated.