KR20010041101A - Digital broadcast receiver - Google Patents

Abstract

The present invention provides a receiver for receiving a broadcast in which multiple channels of data are multiplexed, and auto-presets a channel having a higher bit rate for higher quality or more various services, and provides data of multiple channels having different bit rates. A digital broadcast receiver for receiving a time division multiplexed signal, comprising: data extracting means for extracting data of a specific channel from the time division multiplexed signal, a bit rate detecting means for detecting a bit rate of the channel, and receiving channel information A preset memory is included, and channel information is stored in the preset memory by a bit rate value detected by the bit rate detecting means. Then, the data extraction means performs tuning by extracting the data of the channel specified by the stored channel information.

Description

Digital broadcast receiver {DIGITAL BROADCAST RECEIVER}

Conventional radio receivers have a so-called preset function that stores the reception frequencies of several stations among the receivable broadcast stations in correspondence with a specific preset number so that they can be easily tuned later.

In order to simplify the operation of storing the memory in the preset memory for each radio station equipped with this preset function, and to store it in the preset memory, the auto scan function is used to scan the highest frequency from the lowest frequency of the reception range. There is an auto preset function that stores the received frequency in a preset memory.

However, if the memory is stored up to the maximum number that can be preset before the scan reaches the highest frequency, the scan is terminated. Since the scan is not performed thereafter, the reception state is higher between the frequency at the end of the scan and the highest frequency. There was a problem that even if there were good stations, they were not preset.

As a method of improving this, there is a technique of auto presetting the receiving station described in Japanese Patent Application Laid-Open No. 7-95012 in order of high electric field strength, but a receiver for digital satellite broadcasting in which multiple channels of data are multiplexed on one carrier wave. Since the electric field strength of each channel is the same, there is a problem that this method cannot be used.

SUMMARY OF THE INVENTION The present invention has been made in view of the above situation, and a technical problem is to automatically preset a channel having a higher bit rate or higher service rate in a receiver for receiving a broadcast in which multiple channels of data are multiplexed. do.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a receiver for receiving digital broadcasts, and to a preset technique for storing information of a receiving station in advance in a receiver.

1 is a block diagram of a digital broadcast receiver according to the present invention;

2 is a frame diagram of channel data according to the present invention;

3 is a schematic diagram of a TDM demodulation circuit operation according to the present invention;

4 is a flowchart of control according to the first embodiment of the present invention.

5 is a schematic diagram of a memory table list according to the present invention;

6 is a flowchart of control according to a second embodiment of the present invention.

In order to solve the above problems, a satellite broadcasting receiver according to the present invention is a digital broadcasting receiver for receiving a time-division multiplexed signal of a plurality of channels having different bit rates, comprising: data extracting means for extracting data of a specific channel from the signal; Bit rate detecting means for detecting a bit rate of the channel, and a preset memory for storing received channel information, the channel information being stored in the preset memory by a value of the bit rate detected by the bit rate detecting means, The data extracting means may extract data of a channel specified by the stored channel information.

Hereinafter, an embodiment of the digital broadcast receiver of the present invention will be described with reference to FIGS. 1 to 6.

1 is a block diagram of a digital broadcast receiver according to the present invention.

Reference numeral 1 in the figure is an antenna, and receives radio waves from a broadcast satellite.

Here, the data of each channel of the broadcast wave from the broadcast satellite is multiplexed by TDM (Time Division Multiplexing), and is transmitted after being QPSK modulated.

The frame structure of channel data by this TDM system is shown in FIG.

In the TDM, the time width of each time slot is the same, and the number of bits in each time slot is the same.

Reference numeral 2 is an RF front-end processing unit, which selects a specific broadcast wave from the radio wave received by the antenna 1 and converts it to an intermediate frequency.

The RF front end processing section 2 performs processing by the synthesizer method using the PLL circuit 3 including the programmable divider, but at this time, the division ratio of the programmable divider is controlled by the instruction of the microcomputer 4. To select a reception frequency.

Reference numeral 5 is a QPSK demodulation circuit in which the output of the RF front end processing section 2 is input and the baseband signal is demodulated from a phase modulated carrier.

This demodulation is performed by a synchronous detection method. In addition, this synchronous detection system is well-known technique and detailed description is abbreviate | omitted.

Reference numeral 6 is a TDM demodulation circuit, and is supplied with an output signal of the QPSK demodulation circuit 5, and constitutes and outputs data for each channel.

The TDM demodulation circuit 6 first obtains frame synchronization in the TDM frame synchronization detection section 7 based on the synchronization signal, and after frame synchronization is established, the data in the header section in the TDM header readout section 8 is stored in a microcomputer ( Is read by 4).

As shown in Fig. 3, this header section includes labels 1 to n, which are ID numbers for identifying which channel data each of the time slots 1 to n of the TDM is.

The microcomputer 4 reads from the header which time slot the data of the channel to be received is included in, and inputs a slot number (one or more) into the channel decoder circuit 9.

The channel decoder circuit 9 synthesizes data included in the time slot of the time slot number input from the microcomputer 4 and reconstructs data of one channel.

As a result, the TDM demodulation circuit 6 performs the operation shown in FIG.

This example shows a case in which four channels A, B, C, and D are divided into seven time slots (slots 1 to 7) and transmission is performed.

Channel A is transmitted using time slots 1, 4 and 6, and data of channel A is extracted by extracting and synthesizing data of time slots 1, 4 and 6 from the TDM bit stream for each frame.

In addition, the microcomputer 4 has preset memories P (1) to P (T), and the channel selection information (label or slot number) of the broadcasting station detected by the auto preset processing of the flow shown in FIG. 4 is stored. .

Reference numeral 10 has preset tuning switches P1 to PT and a preset start switch S for calling a broadcast station memorized by the operation switch section.

And the microcomputer 4 performs auto preset process by program control. Although various methods are conceivable for this program control, the following describes the embodiment.

The first embodiment examines how many time slots are used for each channel, stores them in the work memory, and stores them in the preset memory in order from the channels having the large number of used time slots. Therefore, control is performed.

The variables used in this control flow are as follows.

n: Total number of time slots in one frame of TDM.

P (1), P (2),... , P (T): preset memory

LABEL (i): label for time slot i

LABEL_CHK (i): Flag indicating whether the i th label is checked or not

If it is 0, it is not checked. If it is 1, it is checked

LIST (M, 0): Label of Mth channel

LIST (M, 1): Number of slots of Mth channel

COUNT: Variable indicating how many time slots one channel uses

When the preset start switch S is pressed, the microcomputer 4 starts the auto preset process of FIG.

When the processing is started, first, initial value setting is performed in step 1, and the initial values of the variables I and M are set to 1, and the values of the respective label check flags LABEL_CHK (i) to LABEL_CHK (n) are set to zero.

When the initial value setting is completed, the value of the used time slot number counter COUNT is reset in step 2.

Next, in step 3, the value of the label check flag LABEL_CHK (i) of the target label is examined to check whether or not the check has already been completed.

Here, if the check has not yet been performed, i.e., if the value of the label check flag LABEL_CHK (i) is 0, the following method determines how many labels exist from label i + 1 to label n that are identical to label i in steps 4 to 9. Investigate with

In step 4, the value of the variable K is set to i, and in step 5, the matching between the label value of time slot K and the label value of time slot i is checked.

If there is a match, the value of variable COUNT is incremented (step 6).

Then, the label check flag LABEL_CHK (i) of the label i is set to 1, and a flag indicating that the check is completed for i is set.

Next, in step 8, the value of the variable K is incremented, and in step 9 it is checked whether the value of K exceeds the total number n of time slots in one frame of the TDM.

Here, when the value of K does not exceed n, the process of step 5-9 is repeated again.

If the value of K exceeds n, in step 10, a table list of M, the label LABEL (i) of the corresponding time slot, and the COUNT value, which is the number of slots used, is created in the memory.

Next, in step 11, the value of M is incremented, and in step 12, the value of i is incremented.

If LABEL_CHK (i) = 1 in step 3, control is shifted to step 12.

In step 13, the value of i is compared with the value of n.

As a result, when i does not exceed the value of n, control is returned to step 2, and all the channels are checked by performing the process of step 2 to step 13 again.

Thus, the following operation is made.

If the time of one frame is Tf and the number of bits of one time slot is a, the bit rate of each channel is ax number of slots used (COUNT) / Tf.

For example, it is checked whether the channel A using time slot 1 uses the number of slots in the remaining slots 2 to n, and time slot 1 is added to LIST (1, 0) as shown in the table list shown in FIG. Write the number of slots COUNT in the label LABEL (1) = A, LIST (1, 1).

Here, the other slot of the same label A has the flag LABEL_CHK (i) indicating that the check is completed.

Then, it is checked how many slots the channel using the time slot 2 is using, but if the slot 2 has already been checked, LABEL_CHK (2) = 1, the process proceeds to the next without counting.

In addition, when i exceeds the value of n in step 13, the label is stored in T preset memories P (1) to P (T) from the top of the count number with reference to the table list in step 14.

If the counts are the same, they are stored, for example, in the order of the list (small time slot numbers are used).

The preset memory method may be stored in order from the number of counts in addition to the method of storing the upper T counts in list order.

It is also conceivable to store a time slot number (one representative or all slot numbers of the same channel) as a preset memory instead of the label.

After the preset end, when the preset tuning switches P1 to PT are operated, the number of time slots having the same label as that of the memory is input to the channel decoder, and the channel data is reproduced.

Next, a second embodiment of the present invention will be described.

In this embodiment, the label of the header is examined in order, the number of slots counted for each corresponding channel is detected, a table list is created, and the table is referenced with reference to this value. Control is made.

The variables used in this control flow are as follows.

n is the total number of time slots in one frame of the TDM and is a predetermined value.

P (1), P (2),... , P (T): preset memory

LABEL (i): label for time slot i

LIST (M, 0): Array variable to store label corresponding to each channel

LIST (M, 1): Array variable that stores the number of used slots corresponding to each channel.

When the processing is started, first, initial value setting is performed in step 21. LABEL (1) is stored in LIST (1, 0), and 1 is set in LIST (1, 1). In addition, initial values of i and M are set to two.

Next, in step 22, it is determined whether or not something like LABEL (i) exists in LIST (1, 0) to LIST (M-1, 0).

That is, it is determined whether the target channel is new.

Here, if the same as LABEL (i) does not exist in LIST (1, 0) to LIST (M-1, 0), LABEL (i) is set in LIST (M, 0) as a new channel in step 23. LIST (M, 1) is set to one. Thereafter, the value of M is incremented.

In addition, when something like LABEL (i) is present in LIST (1, 0) to LIST (M-1, 0) in step 22, the list corresponding to LABEL (i) of the channel already set in step 24 ( Increment the value of *, 1).

Thereafter, the value of i is incremented in step 25, and steps 22 to 25 are repeated until i exceeds n in step 26.

If i exceeds n in step 26, the labels are stored in the T preset memories P (1) to P (T) from the top of the count number with reference to the table list in step 27.

In this way, it is possible to analyze a digital broadcast signal in which a plurality of channel data are multiplexed, and perform presetting sequentially from a channel having a high bit rate.

As described above, when auto presetting is performed by the digital broadcast receiver of the present invention, broadcasting stations having a large number of time slots, i.e., a bit rate, are preferentially preset.

For example, considering that the music signal is digitized and transmitted, the transmission bit rate is expressed as the product of the sampling frequency and the number of quantized bits (when not compressed). The higher the bit rate is, the higher quality the signal is. Even when broadcasting in multiple languages, etc., it is predicted that the larger the transmission bit rate is, the more channels are transmitted in more languages.

Therefore, the user can easily select a channel that performs a higher quality service or more various services among a plurality of channels of different bit rates.

The present invention is suitable for use in a digital satellite broadcast receiver or the like for receiving a digital broadcast signal multiplexed with a plurality of channel data.

Claims (6)

A digital broadcast receiver for receiving a time-division multiplexed signal of a plurality of channels having different bit rates, Data extraction means for extracting data of a specific channel from the signal; Bit rate detection means for detecting a bit rate of the channel, and A preset memory for storing received channel information, Storing channel information in the preset memory according to the value of the bit rate detected by the bit rate detecting means, And said data extracting means extracts data of a channel specified by said stored channel information. 2. The digital broadcast receiver as claimed in claim 1, wherein channel information is stored in said preset memory in order of increasing bit rate value detected by said bit rate detecting means. The digital broadcast receiver as claimed in claim 1 or 2, wherein the bit rate detecting means detects a bit rate by checking the number of time division multiple time slots used by the specific channel. The method of claim 3, wherein the time division multiplexed signal includes a header storing channel information for each slot in a frame for each frame, And the bit rate detecting means checks the number of time division multiple time slots used by the specific channel based on the channel information of the header. The digital broadcast receiver as claimed in claim 4, wherein the bit rate detecting means repeatedly examines the header information for each channel sequentially. 5. The digital broadcast receiver as claimed in claim 4, wherein the bit rate detecting means counts the number of used time slots of the channel for a channel corresponding to each header information.