ETSI Satellite Digital Radio (SDR or ETSI SDR) describes a standard of satellite digital radio. It is an activity of the European standardisation organisation ETSI.

It addresses systems where a satellite broadcast directly to mobile and handheld receivers in L band or S band and is complemented by terrestrial transmitters. The broadcast content consists of multicast audio (digital radio), video (mobile TV) and data (program guide, text and graphical information, as well as off-line content). The satellite component allows geographical coverage at low cost, whereas the terrestrial component improves reception quality in built up areas. The specifications considers conditional access and Digital Rights Management.[1]

1worldspace planned to use ETSI SDR in its new network covering Europe from 2009, but the company went defunct before it launched its service.[2] Also Ondas Media has announced to use ETSI SDR.[3]

The ETSI SDR is also similar to the Sirius XM Radio, the S-DMB used in South Korea for multimedia broadcasting since May 2005, the China Multimedia Mobile Broadcasting (CMMB) and the defunct MobaHo! service (2004-2009). The DVB-SH specifications, which the DVB Project has created, target similar broadcast systems as ETSI SDR.

ETSI SDR Standard

The ETSI SDR standard allows implementation of parts of such networks in an interoperable way. So far, ETSI has standardized the physical layer of the air interface (radio interface). This allows implementation of demodulators in integrated circuits. The physical layer is described by the following parts of ETSI EN 302 550:

These three parts replace the previous ETSI SDR standards ETSI TS 102 550, ETSI TS 102 551-1 and ETSI TS 102 551-2.

The following technical report contains guidelines for the use of these standards:

The following technical report describes the facts and assumptions on which the SDR standards are based:

Note that in this document the word "may" replaces the word "shall" due to a decision of the ETSI Board in June 2006.

All ETSI specifications are open standards available at ETSI Publications Download Area (this will open ETSI document search engine; free registration is required to download PDF files).

Problems of realization

One of the challenges of implementing an ETSI-SDR system is the nonlinear characteristics of the power amplifier (PA).[4][5] An energy-efficient RF amplifier should consume a small amount of power from the DC source; but unfortunately, there is a trade-off between efficiency and linearity. PASs are most effective when they operate close to saturation, which is also the most nonlinear area of operation. Quadrature Amplitude Modulation (QAM) or Quadrature Phase Shift Keying (QPSK) signals from ETSI-SDR are amplified by a nonlinear amplifier.[6][7] This not only degrades system performance, but also creates out-of-band power leakage that interferes with systems operating in adjacent channels. The problems associated with nonlinearity in PA are very complex.[8][9] A 6-9 dB reduction in input power is common in PA operation and results in reduced efficiency and increased operating costs. Nonlinearity in PA is measured by factors such as the 1 dB compression point, the third-order intercept point (IP3), and the adjacent channel-to-harmonic power ratio. One of the undesirable products of PA nonlinearity is intermodulation distortion (IMD). In an ETSI-SDR system using QAM modulation, IMD manifests itself as an increase in spectrum.[10] This causes in-band distortion and leakage in neighboring channels as a result of spectrum broadening. Increasing the spectrum degrades the signal quality and causes interference in the neighboring channel. Methods are required to mitigate the undesirable effects of PAs in the ETSI-SDR system.

See also

References

  1. ^ ETSI TR 102 525 v1.1.1 (2006-09) Satellite Earth Stations and Systems (SES); Satellite Digital Radio (SDR) service; Functionalities, architecture and technologies
  2. ^ "WORLDSPACE(R) Satellite Radio Signs Fraunhofer IIS to Develop 'Blueprint' for European Satellite Radio Receivers". Archived from the original on 2011-07-18. Retrieved 2009-10-28.
  3. ^ "ONDAS Media: Helping to Set the Standards for Satellite Digital Radio in Europe (Ondas Media)". Archived from the original on 2010-07-08. Retrieved 2009-10-28.
  4. ^ "Design And Implementation Of An ETSI-SDR OFDM Transmitter With Power Amplifier Linearizer". harvest.usask.ca. Retrieved 2024-03-17.
  5. ^ "FPGA Implementation of a Power Amplifier Linearizer for an ETSI-SDR OFDM Transmitter". www.zte.com.cn. Retrieved 2024-03-17.
  6. ^ "A Primer on Quadrature Amplitude Modulation (QAM)". blog.minicircuits.com. Retrieved 2024-03-17.
  7. ^ "Quadrature Amplitude Modulation". www.geeksforgeeks.org. Retrieved 2024-03-17.
  8. ^ "The effects of nonlinear damping on degenerate parametric amplification". link.springer.com. Retrieved 2024-03-17.
  9. ^ "What is satellite radio?". radiostay.com. Retrieved 2024-03-17.
  10. ^ "Quadrature amplitude modulation (QAM): what is it and where is it used". vogueindustry.com. Retrieved 2024-03-17.