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ITU-R REPORT BS.1059-1
Characteristics of single-sideband systems in HF broadcasting
Year: 1990
Abstract: This Report has been developed in recognition that consideration is being given to the progressive introduction of single-sideband broadcasting systems into the bands now allocated to the Broadcasting Service at HF. Introduction of this form of broadcasting can be accomplished with greater technical harmony if there is sufficient guidance concerning the technical parameters involved. The following considerations will be concentrated on single-sideband amplitude modulation with synchronous demodulation. With respect to a necessary transition period from DSB to SSB, some consideration must also be given to the reception of SSB signals with reduced carrier by receivers with envelope detection. At the end of the transition, all of the advantages of SSB transmissions could then be realized, as follows:
— a more efficient utilization of the frequency spectrum and a reduction of interference;
— the capability of improving the required protection ratio between adjacent channels in the case of a sufficient carrier reduction;
— the capability of improving the quality of reception, in particular under poor propagation conditions (selective fading), with SSB receivers.
The modulation technique considered most suitable for the achievement of bandwidth saving is some form of SSB system. WARC-79 Recommendation 501 and No. 302 of the Radio Regulations suggest the use of SSB emissions to the maximum possible extent in AM systems. There are two types of such systems, namely single-sideband (SSB) and compatible single-sideband (CSSB).
The CSSB system is not suitable for use in amplitude-modulated sound broadcasting, principally because of its increased distortion; furthermore, a greater radiofrequency bandwidth is needed and adequate suppression of out-of-band emissions is likely to be difficult at HF.
In the event of the introduction of single-sideband amplitude modulation broadcasting, it would seem desirable to use the definitions existing in Recommendation 326.
According to this Recommendation, the carrier component is defined in relation to the peak envelope power Pp of a radio transmitter, by the acceptable intermodulation level Do.
For single-sideband broadcasting transmitters, the acceptable intermodulation level Dn determines the non-linear distortion (quality), and the out-of-band radiation (adjacent channel interference).
In single-sideband reduced carrier systems, the precision of the locally re-inserted carrier is important for the reception quality.
The system parameters for a future SSB-system for sound broadcasting in band 7 (HF) must be chosen in such a way that the different requirements of the transition period (reception of SSB-signals with receivers using envelope detection) as well as those of the period thereafter, when only receivers with synchronous demodulation will be used, are taken into account [CCIR, 1978-82a].
The system specification of SSB is presented in Recommendation 640.
— a more efficient utilization of the frequency spectrum and a reduction of interference;
— the capability of improving the required protection ratio between adjacent channels in the case of a sufficient carrier reduction;
— the capability of improving the quality of reception, in particular under poor propagation conditions (selective fading), with SSB receivers.
The modulation technique considered most suitable for the achievement of bandwidth saving is some form of SSB system. WARC-79 Recommendation 501 and No. 302 of the Radio Regulations suggest the use of SSB emissions to the maximum possible extent in AM systems. There are two types of such systems, namely single-sideband (SSB) and compatible single-sideband (CSSB).
The CSSB system is not suitable for use in amplitude-modulated sound broadcasting, principally because of its increased distortion; furthermore, a greater radiofrequency bandwidth is needed and adequate suppression of out-of-band emissions is likely to be difficult at HF.
In the event of the introduction of single-sideband amplitude modulation broadcasting, it would seem desirable to use the definitions existing in Recommendation 326.
According to this Recommendation, the carrier component is defined in relation to the peak envelope power Pp of a radio transmitter, by the acceptable intermodulation level Do.
For single-sideband broadcasting transmitters, the acceptable intermodulation level Dn determines the non-linear distortion (quality), and the out-of-band radiation (adjacent channel interference).
In single-sideband reduced carrier systems, the precision of the locally re-inserted carrier is important for the reception quality.
The system parameters for a future SSB-system for sound broadcasting in band 7 (HF) must be chosen in such a way that the different requirements of the transition period (reception of SSB-signals with receivers using envelope detection) as well as those of the period thereafter, when only receivers with synchronous demodulation will be used, are taken into account [CCIR, 1978-82a].
The system specification of SSB is presented in Recommendation 640.
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ITU-R REPORT BS.1059-1
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| contributor author | ITU-R - International Telecommunication Union/ITU Radiocommunication Sector | |
| date accessioned | 2017-09-04T18:34:53Z | |
| date available | 2017-09-04T18:34:53Z | |
| date copyright | 01/01/1990 | |
| date issued | 1990 | |
| identifier other | JHSEUCAAAAAAAAAA.pdf | |
| identifier uri | http://yse.yabesh.ir/std;query=authoCA5893FD081D527369727A00D52FAB6A0Facilities%927ngineering%20Command%226EFDEC9FCD/handle/yse/217061 | |
| description abstract | This Report has been developed in recognition that consideration is being given to the progressive introduction of single-sideband broadcasting systems into the bands now allocated to the Broadcasting Service at HF. Introduction of this form of broadcasting can be accomplished with greater technical harmony if there is sufficient guidance concerning the technical parameters involved. The following considerations will be concentrated on single-sideband amplitude modulation with synchronous demodulation. With respect to a necessary transition period from DSB to SSB, some consideration must also be given to the reception of SSB signals with reduced carrier by receivers with envelope detection. At the end of the transition, all of the advantages of SSB transmissions could then be realized, as follows: — a more efficient utilization of the frequency spectrum and a reduction of interference; — the capability of improving the required protection ratio between adjacent channels in the case of a sufficient carrier reduction; — the capability of improving the quality of reception, in particular under poor propagation conditions (selective fading), with SSB receivers. The modulation technique considered most suitable for the achievement of bandwidth saving is some form of SSB system. WARC-79 Recommendation 501 and No. 302 of the Radio Regulations suggest the use of SSB emissions to the maximum possible extent in AM systems. There are two types of such systems, namely single-sideband (SSB) and compatible single-sideband (CSSB). The CSSB system is not suitable for use in amplitude-modulated sound broadcasting, principally because of its increased distortion; furthermore, a greater radiofrequency bandwidth is needed and adequate suppression of out-of-band emissions is likely to be difficult at HF. In the event of the introduction of single-sideband amplitude modulation broadcasting, it would seem desirable to use the definitions existing in Recommendation 326. According to this Recommendation, the carrier component is defined in relation to the peak envelope power Pp of a radio transmitter, by the acceptable intermodulation level Do. For single-sideband broadcasting transmitters, the acceptable intermodulation level Dn determines the non-linear distortion (quality), and the out-of-band radiation (adjacent channel interference). In single-sideband reduced carrier systems, the precision of the locally re-inserted carrier is important for the reception quality. The system parameters for a future SSB-system for sound broadcasting in band 7 (HF) must be chosen in such a way that the different requirements of the transition period (reception of SSB-signals with receivers using envelope detection) as well as those of the period thereafter, when only receivers with synchronous demodulation will be used, are taken into account [CCIR, 1978-82a]. The system specification of SSB is presented in Recommendation 640. | |
| language | English | |
| title | ITU-R REPORT BS.1059-1 | num |
| title | Characteristics of single-sideband systems in HF broadcasting | en |
| type | standard | |
| page | 17 | |
| status | Active | |
| tree | ITU-R - International Telecommunication Union/ITU Radiocommunication Sector:;1990 | |
| contenttype | fulltext |