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Innovation application: Technology of Spectrum Sliced Transceiver

Title Technology of Spectrum Sliced Transceiver
Abstract

Institute of Telecommunications of Riga Technical University has developed a model of spectrum sliced transceiver (technology), which, by using digital signal processing (DSP), enables the transmission of 1 Gbit/s NRZ sliced broadband electrical signal, using electrical and opto-electrical system components with 500 MHz bandwidth. This model can be customized and improved to meet different individual requirements and applications.

Keywords fiber optical transmission systems, digital signal processing (DSP), optical transceivers
Authors Sandis Spolītis
Vjačeslavs Bobrovs
Ģirts Ivanovs
Sergejs Olonkins
Department (13100) Telekomunikāciju institūts
Statistical Classification of Economic Activities, NACE 2 Manufacture of computer, electronic and optical products
Telecommunications
Scientific research and development
Description of the technology

The electrical and opto-electrical components, which are found in the transmitter and receiver block (transceiver) of the high-speed fiber optical access transmission system, are considered to be its weak point or bottleneck due to the limited frequency bandwidth and the transmission speed. The solution for the limited throughput bandwidth problem that does not require a complete transceiver replacement is an electro-optical spectrum sliced transceiver for high bitrate optical signal transmission and receiving in optical access networks, where, by using digital signal processing (DSP), the electrical baseband signal containing the transmitted information is sliced. Certain parts of the sliced signal are transmitted through the fiber optical access network and the initial signal is restored in the receiver.

Such spectrum sliced transceiver can ensure faster transmission speeds by using the already existing transceivers with a limited frequency throughput bandwidth. This way, the telecommunications service provider can increase the frequency bandwidth of optical access network components multiple times and accordingly the transmission speed. Developed model of spectrum sliced transceiver is shown in figure 1.

Fig. 1. Model of spectrum sliced transceiver using: (a) using time division multiplexing (TDM) or (b) wavelength division multiplexing (WDM) techniques.

Spectrum sliced signal slices can be transmitted one after another using time division multiplexing (TDM) (see Fig. 1a) or parallel by employing wavelength division multiplexing (WDM) (see Fig. 1b). In both cases, the bandwidth of electro-optical and electrical components of the transceiver is scalable and the necessary electrical bandwidth of the high-frequency network hardware is at least two times smaller than in the case of the initial electrical signal before slicing. Prototype of in laboratory constructed spectrum sliced transceiver is shown in figure 2.

Fig. 2. Prototype of spectrum sliced transceiver constructed in laboratory.

It is verified, that by employing forward error correction (FEC) with 7 % of data overhead and ensuring at least the average optical signal power −15.8 dBm received at the photoreceiver, the two slice spectrum sliced transceiver can ensure error-free data transmission with BER<1e−10, by using up to 25 km long optical line with the SMF, DSF, or NZDSF optical fiber types for data transmission.

Applications The developed spectrum sliced transceiver model enables to build more qualitative and scalable high-speed optical transmission systems. In the following research stage, the model by using digital signal processing (DSP), enables the transmission of 1 Gbit/s NRZ sliced broadband electrical signal, using electrical and opto-electrical system components with 500 MHz bandwidth, thus enabling to achieve a higher-speed data transmission using the already existing transmission system infrastructure.
Advantages

Since the spectral slicing technique used in this model is scalable, it means that the electrical signal with N GHz frequency bandwidth can be sliced not only in two signal slices, each taking up Δfslice = N/2 GHz frequency baseband, or in four slices (each taking up Δfslice = N/4 GHz frequency baseband), but even in 10 slices, allowing to integrate this technology in almost any optical transmission system.

This spectrum sliced transceiver technology enables to increase the frequency throughput bandwidth of optical access network components multiple times by using the already existing transceivers with a limited frequency bandwidth.

Technology Readiness Level Technology validated in laboratory
Partnership offer Licence contract or contracts for collaboration.
Publikācijas
ID 39
Contact information email: santa.puskarjova@rtu.lv and ilmars.viksne@rtu.lv; phone number: +371 29373757 un +371 29187403