DE3220278C2 - Method for transmitting a digital, high-quality, stereophonic radio program signal - Google Patents

Abstract

In the present case, a method is proposed for transmitting a digital, high-quality, stereophonic radio program signal via a hierarchical level of digital signal connections with a bit rate which corresponds to half the bit rate of the hierarchical level, preferably 2 Mbit / s. In order to be able to output the bit stream of the radio program signal together with further additional information together with further additional information with a bit sequence which can easily be derived from the bit sequence clock of the 2 Mbit / s digital signal connection hierarchy, the net bits of the radio program signal to be transmitted are supplemented by empty bits so that the Bit rate of the supplemented radio program signal corresponds to an integer part of the bit rate of the hierarchy level.

Description

supplemented radio program signal exactly one while avoiding known clock adjustment techniques integer part of the bit rate of the hierarchy - the insertion of the digital broadcast program signal

in a simpler way without accepting more possible

chiestufe corresponds

2. The method according to claim 1, characterized in that the bit rate corresponds to '/ ^ - times the bit rate of the hierarchy level, where χ is an integer from 0 to π .

The invention relates to a method according to the preamble of claim 1.

It is known when setting up digital transmission networks (Telcom Report, Volume 2, 1979, supplement "Digital transmission technology", pp. 52-64), bit streams lower data rate in multiplex devices and in bit streams of higher hierarchies with insert higher bit rate. On the receiving side, the composite bit streams are in Demultiplexing devices are broken down and the bit streams with lower data rates are recovered from them.

When transmitting high quality broadcast program signals in digital form, the usual way the analog audio signal is sampled with 32 kHz sampling frequency, each sample with 14 bit resolution analog / digital converted and each sample value is protected by adding a parity bit. For a Such a digital, stereophonic program signal therefore has a bit stream of 32kHz-15 bit 2 = 960 kbit / s to be transported. This 960 kbit / s are in a bit stream of 2048 kbit / s, according to the 2 Mbit / s digital network hierarchy of the CCITT transport (CCITT-Orange Book, Vol. 3-2, See. 7, Geneva ITU 1977). This 2048 kbit / s bit stream should also be mixed with telephone channels and Radio program signals are occupied. The introductory

15th

To enable quality losses.

According to the invention, this object is achieved by the characterizing features of claim 1. A preferred embodiment of the method according to claim 1 results from the dependent claim.

The invention is based on the consideration of combining the 960 kbit / s bit stream of the broadcast program signal with further additional information with a bit sequence that can easily be derived from the bit sequence clock derive from the 2 Mbit / s digital signal connection hierarchy leaves, whereby an automatic synchronicity with the 2048 kbit / s cycle of the network is enforced. For this purpose, in the method according to the invention, the signal transfer interface (radio studio / postal network interface) existing 2.048 MHz frequency divided by 2 using a flip-flop frequency divider to gain 1.024 MHz from it. These 1.024 MHz are used to initially generate a frame sync word output bit by bit, which consists of 8 to 15 bits per frame duration of 4 ms, 960,000 bit / s of the broadcast program signal and 32,000 bit / s for additional signals. Furthermore, the 1.024 MHz are used to gain and Synchronization of the 32 kHz sampling frequency used. Because of the structure and the most flexible possible Use of the 2 Mbit / s digital network hierarchy cannot use all 512 bits of a pulse frame of 250 us duration be occupied. The reason for this is that for

Frame detection and other operational information bits are to be left so that the available The net bit rate for two high-quality radio program signals, for example, is only 1980 kbit / s, or 900 kbit / s with half occupancy. This in turn means that the bit repetition rates i; only at most

_γ ._ _{ο dw} 990 kHz instead of 1.024 MHz. On the other hand needs

transmission of the radio program signal with 960 kbit / s in 50 one for the 32 kHz audio signal sampling on the the 2048 kbit / s pulse frame of the digital network could send and receive a frequency from which easily done in such a way that every time the 32 kHz are to be derived, which is a at 990 kHz Pulse frame of the radio program signal arrives, means divider factor of 30.9375 and only very enough time slots for the outgoing 2048 kbit / s pulse would be expensive to implement. This effort can be frame are available for complete recording. 55 according to the invention by reducing the

___ - λ λ m t «- ^ 1 i. t_ _ 'J - _ η I i ■ - ._J t f _ ^ λ!. ^ __ 1 *! Λ · * **! «« ** D. ^ Al «η iiAn

Due to the lack of frequency coupling between the two pulse frames, this requirement is often not met. so that in one case bits of the incoming pulse frame either not at all or only in the the next time slot of the outgoing pulse frame 60 which can be transmitted or in the other case Bit positions remain unoccupied in the outgoing pulse frame and must be supplemented ("stuffed"). Such a one Clock adjustment technology is, for example, from »Round

radio technical messages "Vol. 24, 1980, pp. 31-36 and 65.

Sync bits and information bits appends a series of empty bits that do not contain any information, just make sure that the bit rate of 1.024MHz is reached. This is once easy derivation from 2.048MHz possible and, on the other hand, the required 32 kHz sampling frequency can easily be synchronized with it (1.024 MHz: 32 kHz = 32), as there is a simple binary divider with a factor of 32 (5 flip-flop levels)

Claims (1)

Claims: 207-211 known in connection with the connection of plesiochronous digital networks. When using such a clock adaptation technique, it is necessary to "inform" the receiving-side demultiplexer whether and which of the two cases mentioned has occurred in order to ensure its proper functioning. Both this "communication" and its evaluation require a correspondingly increased effort for the entire network 1. Procedure for transmitting a digital, high-quality, stereophonic broadcast program signal via a hierarchical level of digital signal connections with a bit rate which is approximately half the bit rate of the hierarchy level corresponds, thereby marked- net, that the net bits of the io to be transmitted regardless of the possibly occurring loss of quality, supplement the broadcast program signal with empty bits if bits cannot be transmitted,
be in such a way that the bit rate of the The object of the invention is accordingly