This standard specifies the main technical characteristics of the shortwave (HF) broadcast single sideband (SSB) standard transmission and receiving systems. This standard also gives the basic technical requirements for double sideband (DSB) amplitude modulation receivers using envelope detection to receive SSB (H3E) signals compatibly. This standard applies to shortwave (HF) broadcast transmission and receiving systems of the SSB standard, and can also be used as a technical basis for the production of SSB shortwave broadcast transmitters and receivers. GB/T 15960-1995 Technical Specifications for Shortwave (HF) Broadcast Single Sideband Standard GB/T15960-1995 Standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
GB/T15960—1995
Single sideband (SSB) system specifications for HF broadcasting
Issued on December 22, 1995
State Administration of Technical Supervision
Implementation on August 1, 1996
National Standard of the People's Republic of China
Single sideband (SSB) system specifications for HF broadcasting
This standard is equivalent to ITU-RBS.640-1. 1 Subject content and scope of application
GB/T15960—1995
This standard specifies the main technical characteristics of the transmitting and receiving systems of the shortwave (HF) broadcasting single sideband (SSB) system. This standard also gives the basic technical requirements for double-sideband (DSB) AM receivers using envelope detection to receive SSB (H3E) signals compatibly.
This standard applies to SSB shortwave (HF) broadcast transmission and reception systems, and can also be used as a technical basis for the production of SSB shortwave broadcast transmitters and receivers.
2 Reference standards
GB6933 Shortwave single sideband transmitter electrical performance measurement method GB6934 Shortwave single sideband receiver electrical performance measurement method GB7400.2 Broadcasting and television terminology Radio broadcasting 3 Terms
Except for the following terms, the definitions of terms involved in this standard comply with the provisions of GB7400.2. 3.1 Degree of carrier reduction The degree to which the carrier output power of the transmitter is reduced relative to its peak envelope power. 3.2 Unwanted sideband (lower sideband) suppression The degree of suppression of the unwanted sideband signal (including the intermodulation products in this part of the spectrum of the transmitter) during the generation of the single sideband signal. Its value is expressed in decibels (dB) of the unwanted sideband signal level relative to the useful sideband signal level. 3.3 Intermodulation distortion (intermodulation products) Intermodulation distortion (intermodulation products) When a signal with two or more frequency components passes through a channel, a new non-harmonic component is generated due to the nonlinearity of the channel. Its size is measured by the decibel number (dB) of any maximum level of all intermodulation components relative to the level of one of the two signals when the two-tone equal-amplitude signal modulated transmitter outputs the rated peak envelope power. 3.4 Receiver noise limited sensitivity noise limited sensitivity of the receiver The ability of the RF part of the receiver to receive weak signals. Its size is equal to the minimum value of the RF input signal required to obtain the specified signal-to-noise ratio at the receiver audio output, expressed in dB (μV). 3.5 Frequency tolerance frequency tolerance The maximum allowable deviation of the transmitted carrier frequency from the assigned frequency, or the transmitted characteristic frequency from the reference frequency. The frequency tolerance is expressed in Hertz (Hz).
Approved by the State Administration of Technical Supervision on December 22, 1995, and implemented on August 1, 1996
4 Main technical requirements
4. 1 SSB transmission
GB/T15960—1995
4.1.1 Audio bandwidth: The audio bandwidth (-3dB) of the transmitter is: 150Hz~4.5kHz, the attenuation slope of frequencies above 4.5kHz is 35dB/kHz, and the frequency below 150Hz is attenuated at a slope of 6dB/oct. 4.1.2 Necessary bandwidth: not more than 4.5kHz. 4.1.3 Modulation processing characteristics: After the audio signal is modulated, the modulated signal must maintain a dynamic range of not less than 20dB. 4.1.4 Channel spacing: 5kHz. (10kHz during the transition period to the SSB standard) 4.1.5 Nominal carrier frequency: integer multiples of 5kHz. 4.1.6 Transmit sideband: Use upper sideband.
4.1.7 Unused sideband suppression
The suppression of unused sidebands should meet the requirement of 40dB lower than the useful sideband signal level. When the carrier reduction is 6dB (H3E, single sideband, full carrier), the unused sideband suppression should be at least 25dB. 4.1.8 Carrier reduction: 12dB. (R3E, single sideband, reduced amplitude carrier) (During the transition period to SSB standard, in order to enable DSB receivers with envelope detection to receive SSB transmission signals without excessive deterioration of reception quality, the carrier reduction is 6dB.) 4.1.9 Frequency tolerance: ±5Hz.
4.1.10 Intermodulation distortion: at least 35dB.
4.2 SSB reception
4.2.1 Overall selectivity of the receiver: The overall bandwidth (-3dB) of the reference receiver is 4kHz, and the frequency attenuation slope outside this bandwidth is 35dB/kHz. Www.bzxZ.net
4.2.2 Noise-limited sensitivity of the receiver: When the modulation index is 30% and the audio signal-to-noise ratio is 30dB, the noise-limited sensitivity value of the SSB receiver is better than 30dB (μV).
4.2.3 Demodulation system of the SSB receiver: A synchronous demodulator is used. In order to obtain the carrier, a method of replicating the carrier by making the receiver phase-locked to the control loop of the input signal is used, so that it can be used to receive both SSB and DSB transmission signals. 4.2.4 Image suppression of the SSB receiver: at least -40dB. 4.3 Measurement method
Measured in accordance with the provisions of GB6933 and GB6934. Additional remarks:
This standard is proposed by the Ministry of Radio, Film and Television of the People's Republic of China. The Standardization Planning Institute of the Ministry of Radio, Film and Television is responsible for the technical coordination of this standard. The Science and Technology Department of the Ministry of Radio, Film and Television is responsible for drafting this standard. The main drafter of this standard is Ding Dongyi.
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