JP2001257659A - Method and device for measuring bit error rate depending on layer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and device for measuring a bit error rate depending on layers that can accurately obtain the bit error rate by each modulation system for hierarchical transmission. SOLUTION: Transmission mode separators 3, 4 separate data before Reed- Solomon error correction and data after the Reed-Solomon error correction on the basis of transmission mode/slot information in TMCC information from a TMCC analyzer 2 according to a transmission mode and a coding rate. Comparators 5, 7, 9, 11 compare the separated data before the Reed-Solomon error correction with the separated data after the Reed-Solomon error correction by the same transmission mode and each coding rate. Error counters 6, 8, 10, 12 count bits dissident through the comparison as error bits so as to obtain the bit error rate by the same transmission mode and by each coding rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a method and apparatus for measuring a bit error rate for each layer used for evaluating reception performance in a digital satellite broadcast receiving apparatus or the like.

[0002]

2. Description of the Related Art Hierarchical transmission technology is used for digital broadcasting. When measuring the bit error rate after Reed-Solomon decoding in this digital broadcast reception, by the approximate number of symbol errors at the time of Reed-Solomon decoding, or by the number of bit errors calculated after Reed-Solomon decoding by return transmission from the transmission system, It was roughly estimated.

[0003]

However, according to the conventional method of measuring the bit error rate using an error rate that can be estimated at the time of Reed-Solomon decoding, the error value is estimated in byte units, and thus the reception C / N As for the BER (bit error rate), the range of the error is widened as shown by the broken line in FIG.
That is, there is a problem that only a coarse bit error rate can be measured and an accurate bit error rate cannot be measured.

[0004] In addition, even if the number of bit errors calculated at the time of Reed-Solomon decoding by return transmission from the transmission system is used, a bit error rate cannot be obtained for each modulation scheme of hierarchical transmission.

An object of the present invention is to provide a method and apparatus for measuring a bit error rate for each layer, which can accurately obtain a bit error rate for each modulation scheme of hierarchical transmission.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a method for measuring a bit error rate for each layer, wherein data before Reed-Solomon error correction and data after Reed-Solomon error correction in a receiving apparatus for receiving a broadcast by hierarchical transmission are transmitted to a TMCC. Separated according to the transmission mode and coding rate based on the transmission mode / slot information in the information, and compared the separated data before Reed-Solomon error correction and the data after Reed-Solomon error correction for each same transmission mode and coding rate Then, the number of bits that do not match in the comparison is counted to determine the bit error rate for each of the same transmission mode and coding rate.

A hierarchical bit error rate measuring apparatus according to the present invention extracts a transmission mode / slot information in TMCC information from data after Reed-Solomon error correction in a receiving apparatus for receiving a broadcast by hierarchical transmission.
A C analyzer; separating means for separating data before Reed-Solomon error correction and data after Reed-Solomon error correction based on the transmission mode / slot information in the TMCC information according to the transmission mode and the coding rate; The data before Reed-Solomon error correction and the data after Reed-Solomon error correction are compared for the same transmission mode and coding rate, and the bits that do not match by the comparison are detected for the same transmission mode and coding rate. It is characterized by comprising a comparing means and an error counter for counting the number of bits detected by the comparing means for each transmission mode and coding rate.

According to the bit error rate measuring method and apparatus for each layer according to the present invention, the data before the Reed-Solomon error correction and the data after the Reed-Solomon error correction are TMC-based.
The data before the Reed-Solomon error correction and the data after the Reed-Solomon error correction are separated according to the transmission mode and the coding rate based on the transmission mode / slot information in the C information. And the bits that do not match by the comparison are counted, and the bit error rate for each transmission mode and coding rate is determined.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method and apparatus for measuring a bit error rate for each layer according to the present invention will be described with reference to embodiments.

FIG. 1 is a block diagram showing a configuration of a hierarchical bit error rate measuring apparatus to which a hierarchical bit error rate measuring method according to an embodiment of the present invention is applied, and FIG. FIG. 3 is a block diagram illustrating a part of a receiving device in which the error rate measuring device is used.

A receiving apparatus using a hierarchical bit error rate measuring apparatus to which a hierarchical bit error rate measuring method according to an embodiment of the present invention is applied, as shown in FIG.
The S signal is supplied to a front end 21, a signal of a reception channel is selected, supplied to an A / D converter 22 and converted into digital data, and output data from the A / D converter 22 is 8PSK, QPSK, The signal is supplied to the BPSK demodulation circuit 2 and demodulated. In the clock recovery circuit 24, a clock is recovered based on the demodulated output.

8PSK, QPSK, BPSK demodulation circuit 2
Is decoded by a trellis / Viterbi decoder 25, and a synchronizing signal is detected by a synchronizing signal detecting circuit 26 from the error-corrected data in the trellis / Viterbi decoder 25.

The data error-corrected in the trellis / Viterbi decoder 25 is supplied to a deinterleave / descramble circuit 27, where the data is deinterleaved and descrambled.

The deinterleaved and descrambled data is supplied to a Reed-Solomon decoder 28, where the data is subjected to error correction and output as a transport stream.

Deinterleaving and descrambling circuit 2
7, the input data of the Reed-Solomon complex 28 and the output data of the Reed-Solomon complex 28 are supplied to the hierarchical bit error rate measuring device 1 and the bit error rate is measured.

As shown in FIG. 1, a hierarchical bit error rate measuring apparatus 1 to which a hierarchical bit error rate measuring method according to an embodiment of the present invention is applied, as shown in FIG. The corrected data is supplied to a transmission mode-specific separator 3 that separates the data by transmission mode and coding rate. The data before Reed-Solomon error correction is separated from the data before Reed-Solomon error correction by transmission mode and coding rate. To the transmission mode-specific separator 4.

On the other hand, the data error-corrected by the Reed-Solomon decoder 28 is TMCC (Transmission and MCC).
ultiplexing Configuration Control) analyzer 2, extracts the transmission mode / slot information in the TMCC information in the TMCC analyzer 2, and supplies the transmission mode / slot information to the transmission mode-specific separators 3 and 4. Based on the transmission mode / slot information, the transmission mode separators 3 and 4 separate the transmission mode and coding rate.

The data after the Reed-Solomon error correction and the data before the Reed-Solomon error correction separated by the transmission mode and the coding rate in the transmission mode-specific separators 3 and 4 are compared by the comparator 5 for the same transmission mode and the coding rate. , 7, 9, and 11 to compare the data after the Reed-Solomon error correction and the data before the Reed-Solomon error correction separated by the same transmission mode and coding rate to obtain the same transmission mode and code. Error bits are detected by detecting, for each of the same transmission mode and coding rate, bits that do not match the data after Reed-Solomon error correction and the data before Reed-Solomon error correction that are separated for each coding rate.

The error bit based on the comparison result from the comparator 5 is supplied to an error counter 6 to count the number of error bits. The error bit based on the comparison result from the comparator 7 is supplied to an error counter 8 and The number of error bits based on the result of comparison by the comparator 9 is supplied to an error counter 8 to count the number of error bits.
To count the number of error bits. As a result, the bit error rate for each transmission mode and coding rate can be obtained based on the count values of the error counters 6, 8, 10, and 12 that have counted the number of error bits.

FIG. 3 shows an example of the reception C / N versus the bit error rate measured by the above-described bit error rate measuring apparatus 1 for each layer.

The separated transmission mode and coding rate are 8
Type, BPSK (1/2), QPSK (1/2), QP
SK (2/3), QPSK (3/4), QPSK (5 /
6), QPSK (7/8) and 8PSK (2/3). Here, () shows the coding rate.

FIG. 1 illustrates a case where four comparators are provided. When provided independently for each transmission mode and coding rate, it is necessary to provide eight comparators, but main signals of different transmission modes and coding rates are not transmitted simultaneously. Therefore, it is possible to respond by selecting a comparator according to an error detection instruction based on a transmission mode and a coding rate of a transmitted main signal and performing a comparison operation to detect an error. For example, the comparator and the error counter may be one set.

When the bit error rate measuring apparatus 1 for each layer uses the data after Reed-Solomon correction in order to perform accurate error measurement for each transmission mode and coding rate, the transmission mode is independently set for the bit error rate. Can be measured accurately.

The reason is that, in the layered transmission system, the modulation can be changed in slot units, so that the bit error rate for converting the data after the Viterbi decoded signal into symbols has a rate error in the transmission system with a small number of slots. This is because the bit conversion can be performed in the Reed-Solomon correctable range at the time of Reed-Solomon decoding, so that the error can be reduced.

[0025]

As described above, according to the bit error rate measuring apparatus for each layer of the present invention, the bit error rate of received data can be accurately measured for each transmission mode and coding rate.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a hierarchical bit error rate measuring apparatus to which a hierarchical bit error rate measuring method according to an embodiment of the present invention is applied.

FIG. 2 is a block diagram showing a part of a receiving device in which the hierarchical bit error rate measuring device according to one embodiment of the present invention is used.

FIG. 3 is a diagram illustrating an example of a bit error rate measured by the hierarchical bit error rate measuring device according to the embodiment of the present invention.

FIG. 4 is a diagram showing an example of a bit error rate measured by a conventional bit error rate measuring device.

[Explanation of symbols]

 Reference Signs List 1 Bit error rate measuring device for each layer 2 TMCC analyzer 3 and 4 Separator for each transmission mode 5, 7, 9 and 11 Comparator 6, 8, 10 and 12 Error counter

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takahiro Wada 1-16-1 Hakusan, Midori-ku, Yokohama-shi Kenwood Tea M I. Co., Ltd. (72) Inventor Akihiro Horii 1-1-14 Dogenzaka, Shibuya-ku, Tokyo No. 6 F-term in Kenwood Corporation (reference) 5B001 AA11 AC05 AD06 AE02 5J065 AA01 AB01 AC02 AD10 AD11 AG06 AH15 5K014 AA01 BA08 BA11 EA08 FA16 GA02

Claims (2)

[Claims] 1. A method for receiving data before Reed-Solomon error correction and data after Reed-Solomon error correction in a receiving apparatus for receiving a broadcast by hierarchical transmission to a transmission mode and a coding rate based on transmission mode / slot information in TMCC information. Therefore, the separated data before the Reed-Solomon error correction and the separated data after the Reed-Solomon error correction are compared for the same transmission mode and coding rate,
A bit error rate measurement method for each layer, wherein bits that do not match by comparison are counted to determine a bit error rate for each transmission mode and coding rate. 2. A method for receiving TMC from data after Reed-Solomon error correction in a receiving apparatus for receiving broadcasting by hierarchical transmission.
A TMCC analyzer for extracting transmission mode / slot information in C information; and a transmission mode and coding rate of data before Reed-Solomon error correction and data after Reed-Solomon error correction based on the transmission mode / slot information in TMCC information. Separating the data before the Reed-Solomon error correction and the data after the Reed-Solomon error correction, separated by the separating means, for each same transmission mode and coding rate. Means for detecting the same for each transmission mode and coding rate; and an error counter for counting the number of bits detected by the comparing means for each transmission mode and coding rate. Rate measuring device.