KR20030076012A - Method for detecting physical channel transmitting format - Google Patents

Abstract

PURPOSE: A method for detecting a physical channel transmission format is provided to detect a transmission format exactly by differently granting the weight value of a correlation value according to the bias level of the correlation value in order to detect the transmission format of a received signal. CONSTITUTION: As a PDCCH(Packet Data Control CHannel) is transmitted at one of slot mode 1, slot mode 2 and slot mode 4, a receiving block executes decoding for every mode. In case that a decoding result is not satisfactory, the receiving block applies a regeneration method using a regeneration block. At this moment, a bias is generated in the correlation values of the signals received at a specific mode and the correlation values of regenerated signals. In order to ease such a bias, the receiving block applies a previously calculated weight value to each correlation value using simulation or a field test.

Description

Method for detecting physical channel transmitting format

The present invention relates to physical channel transmission format detection, and more particularly, to a physical channel transmission format detection method suitable for detecting a transmission format of a received signal more accurately.

When a transmitter transmits some data to a receiver, a system that does not inform the receiver of information about the data transmitted by the transmitter will decode all the various formats that can be received for the received data.

That is, in some types of wired and wireless communication systems, a specific physical channel may be transmitted in various formats (various types of lengths), but the receiving side may transmit the channel without clear information about the transmission format. There are times when you need to receive. Therefore, the receiving end should perform blind format detection. An example of such a system is the 1x-EVDV system (CDMA 2000-Revision-C), which is being developed as a next generation mobile communication system.

In the 1x-EVDV system, the F-PDCCH is used to transmit control information of the F-PDCH, which is a physical channel for transmitting packet data.

That is, conventional wireless communication systems for packet data transmission use physical channels such as a packet data channel (PDCH) and a packet data control channel (PDCCH) for packet data transmission. .

The PDCH is actually a channel for transmitting packet data to be transmitted to the corresponding terminal (or user, hereinafter referred to as terminal).

The PDCCH includes control information that enables the terminal to properly receive data transmitted through the PDCH without error.

In this case, the PDCCH is a control channel for using a packet data channel (PDCH) as a forward channel. The PDCCH transmits information necessary for decoding in order to decode data transmitted through the PDCH at the receiving end.

Basically, the current PDCCH has 6 to 8 bits of cyclic redundancy checking (hereinafter referred to as CRC) bits to check various information necessary for decoding of 13 to 21 bits and whether there is a reception error of the information. bit) and an 8-bit convolutional encoder tail bit.

A total of 27 to 37 bits of information thus constructed is convolutional coding of 1/2 or 1/4, and 54 to 64 bits of coded bit (for 1/2 coding) or 108 Produces ~ 128bit of coded bit (1/4 coding).

After performing such blind detection on the F-PDCCH, it is possible to determine the format that produces the best result as the transmission format at the transmitting end and to obtain the transmitted data.

The various types of transmission formats referred to herein include the number of bits of data, the coding method, the coding rate, the repetition and puncturing, the interleaving method, the frame length, and the like. It includes all types of communication structures.

Hereinafter, a physical channel transmission format detection method according to the prior art will be described with reference to the accompanying drawings.

1 is a block diagram illustrating a transmission chain block of a general transmitter, FIG. 2 is a block diagram illustrating a transmission chain block of an F-PDCCH of a CDMA2000 1xEV-DV system according to the prior art, and FIG. 3 is a receiver chain of a receiver according to a prior art example. It is a block diagram.

1 is a block diagram illustrating a transmission chain block of a general transmitter, and FIG. 2 is a block diagram illustrating an F-PDCCH of a CDMA2000 1xEV-DV system according to the prior art.

The data (input sequence) transmitted to the F-PDCCH of the CDMA2000 1xEV-DV system according to the prior art is added with an error detection code such as a CRC code in the error detection code addition block 10.

The bit to which the CRC code is added is added with tail bits for sending the final state of the encoder to a known termination in the tail bit addition block 20.

The bits to which the tail bits are added are encoded by the convolutional code in the encoder 30.

The encoded bits generated through this process are symbolly repeated and punctured according to the length of the slot transmitted by the symbol repetition and puncturing block 40 according to the length of the slot to be transmitted.

For example, due to the limitation of the number of Walsh codes available in 1x EVDV systems, the PDCCH uses Walsh codes of 64 chips in length. Therefore, the number of coded bits per slot is 48 bits.

In the PDCCH, since slots used for transmission are 1, 2, and 4 slots, 48 coded bits are used for 1 slot and 96 slots are used for 2 slot. A coded bit and 4 slot lengths contain 192 coded bits.

The punctured bits are interleaved in the block interleaver 50 and modulated by the QPSK scheme in the modulator 60. This modulated signal is separated into I and Q channels using some of the Walsh codes.

In this case, as described above, the transmission length of the F-PDCCH may be 1 slot, 2 slots, or 4 slots, where the slot means a time unit of 1.25 msec. At this time, as described above, the transmitting end does not inform the receiving end of the length of the F-PDCCH being transmitted. That is, the receiving end can not clearly know what format the transmission format.

3 is a block diagram illustrating a reception chain block of a receiver according to an example of the related art, and includes a demodulator 70 for demodulating a received signal, a deinterleaver 80 for deinterleaving, a depuncturing block 90 and a decoder for depuncturing ( 100) and the error detection block 110, and in the reverse order to the configuration of the transmitter of FIG. Such a receiving end corresponds one-to-one to one format that can be transmitted.

Therefore, the receiver, as shown in FIG. 3, has three formats (three slots: one slot, two slots, and the like) for transmitting the received data in order to know what the transmission length (or format) of the received F-PDCCH is. The decoder 100 performs a decoding process for all four slots, and checks a cyclic redundancy checking (CRC) in the error detection block 110.

That is, when data is transmitted in one transmission format, the receiving end stores the data in the receiving buffer and decodes the data in all transmission formats that can be transmitted for the received data. At 110, a CRC check is performed.

That is, when the decoder 100 finally performs CRC check on the data obtained through decoding and passes it, the decoder 100 recognizes the format applied when the format is transmitted and transmits the data obtained therefrom. Treated as data.

For example, if a transmission format of a system is transmitted by convolutional coding using one of three of 1/2, 1/3, and 1/4 coding rates (other than that) It is assumed that the conditions of are all the same.) When the transmitting end transmits data to the receiving end using any one of the three transmission formats, the receiving end has no information on the received data, and thus the blight detection of the received data is performed. (blind detection) is performed.

First, all three formats that can be transmitted are decoded on the received data. That is, they are decoded through 1/2, 1/3, and 1/4 coding rates. Subsequently, the CRCs of the decoded data are checked and recognized as the transmitted format.

However, since blind detection has no information on the transmission format of the received data, and the received channel condition is not always satisfactory, the probability of success is not very high.

For this reason, the probability of CRC success for a transport format other than the transport format actually transmitted cannot be ignored, and a supplementary measure is necessary.

One method is to perform regeneration on the decoded information as shown in FIG. 4 to compare the reliability of various transmission formats.

4 is a block diagram illustrating a reception chain block of a receiver according to another example of the prior art, and FIG. 5 is a diagram for describing a transmission format detection method according to the prior art.

4 is a block for regeneration being added to a reception chain block configuration of a receiver according to the prior art example as shown in FIG. 3, and a dotted line portion is a regeneration block 120 for regeneration.

This method first applies the same format again in the regeneration block 120 to the decoded data in each format to produce a signal of the same type as the received signal.

The signals thus produced are compared with the signals actually received and select the format that shows the least error among them, and recognize the data obtained through the transmission format as shown in FIG. 1 or 2.

First, the data having been decoded in each format is re-applied in the regeneration block 120 to re-apply the formats used for each encoding to regenerate a signal having the same form as the received signal (S10 and S11).

Then, the received signal and the regenerated signal are correlated (S12). That is, a correlation method is used as one method of comparing the received signal with the regenerated signal.

In the example above, if the received signal and the signal regenerated by the three formats are shown in Table 1,

Receiving signal -0.56 -3.28 -4.29 5.33 1.26 0.08 -3.3 Format 1 +1 -One +1 +1 -One -One -One Format 2 -One -One -One +1 +1 +1 -One Format 3 -One -One -One -One -One +1 -One

The correlation value for format 1 is 4.27, the format 2 is 18.1, format 3 is 4.92, and the correlation value for format 2 is the largest. At this time, the data obtained through format 2 is determined as the data transmitted from the transmitting end.

However, when a correlation value is obtained for each format as described above, a bias may occur in the correlation value depending on the characteristics of the system. In other words, there is a correlation between the signal regenerated using a particular format and the received signal, which means that even though the value regenerated in a particular format is not correct, It may be printed. In this case, the original intention for finding the optimal data through regeneration cannot be satisfied, so that accurate transmission format detection cannot be performed.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and weights of correlation values according to the degree of bias of correlation values generated for a specific format in a method of using correlation values to detect a transmission format of a received signal. The present invention provides a method for detecting a physical channel transmission format which can detect a transmission format more accurately by differently assigning different values.

According to one aspect of the present invention, the method comprising the steps of decoding the received signal for all transmission formats of the transmission side, encoding the decoded received signals in the respective transmission format to regenerate the received signals, Detecting a transmission format having a largest correlation value according to a result of adding a weight according to a bias of a correlation value generated in each of the transmission formats when correlating the received signal with the regenerated received signals. Is done.

Preferably, the method further includes correlating the received signal with the regenerated received signals to detect respective correlation values, and calculating the weights on the detected correlation values.

The weight is set in advance by using a simulation or field test for each of the transmission formats at a receiving side receiving the received signal.

1 is a block diagram of a transmission chain of a general transmitter

2 is a block diagram illustrating a transmission chain block of an F-PDCCH in a CDMA2000 1xEV-DV system according to the related art.

3 is a block diagram illustrating a reception chain block of a receiver according to a prior art example.

4 is a block diagram illustrating a reception chain of a receiver according to another example of the related art.

5 is a view for explaining a transmission format detection method according to the prior art.

6 is a view for explaining a transmission format detection method according to the present invention.

Hereinafter, a configuration and an operation according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

6 is a view for explaining a transmission format detection method according to the present invention.

The present invention grasps in advance the degree of bias (output strength) of a correlation value generated for a specific transmission format in a step S12 of obtaining a correlation value among the transmission format detection methods in the prior art as shown in FIG. Based on this, we propose a method of weighting each correlation value. This alleviates the bias of each correlation value and enables more accurate blind detection.

For example, the PDCCH, which is a forward channel of the CDMA2000 1xEV-DV system as shown in FIG. 2, is modulated and interpolated and then transmitted in 1 slot, 2 slots, or 4 slots. . Therefore, in order to correctly receive the PDCCH transmitted by the base station, the terminal always stores the received signal in a buffer and performs blind detection.

In this case, as described above, since the PDCCH is transmitted in one of 1 slot mode, 2 slot mode, or 4 slot mode, the receiver performs decoding in each mode. If the decoding result is not satisfactory, a regeneration method using the regeneration block 120 is applied as shown in FIG. 4. In this case, since bias may occur in the correlation value between the received signal and the regenerated signal for a specific mode, the pre-calculated using simulation or field test to mitigate such bias. A weight value is applied to each correlation value (S20).

That is, if the correlation value generated through the format of one slot mode is corr1, the two slot mode is corr2, and the four slot mode is corr3, as shown in FIGS. 4 and 5. In the same prior art, three corr1, corr2, and corr3 values are compared to select a format having the largest value.

However, in the present invention, if each weighting value is a1, a2, a3, the slot mode format having the largest value among the corr1 * a1, corr2 * a2, and corr3 * a3 values is selected and transmitted using the same. It finds a piece of data.

If a simulation of three formats results in a correlation value for format 3, a correlation value generated using format 3 is generated when the correlation value is relatively large regardless of whether the data is right or wrong compared to the other two formats. By applying a specific weight to the bias, much of the bias can be mitigated.

It will be apparent to those skilled in the art that the present invention in the above description can be variously modified and changed without departing from the spirit and scope of the invention as indicated by the claims.

In the physical channel transmission format detection method according to the present invention, the degree of bias of a correlation value generated for a specific format in the process of obtaining a correlation value is determined in advance, and weighting is applied to each correlation value based on this data. By using the method of adding, the bias of each correlation value is alleviated, so that an accurate blind detection can be performed.

Claims (3)

Decoding the received signal for all transmission formats that can be transmitted by the transmitting side; Regenerating the received signals by encoding the decoded received signals into the respective transmission formats; Detecting a transmission format having a largest correlation value according to a result of adding a weight according to a bias of a correlation value generated in each of the transmission formats when correlating the received signal with the regenerated received signals. And physical channel transmission format detection method. The method of claim 1, Correlating the received signal with the regenerated received signals to detect respective correlation values; And calculating the weight on the detected correlation value. The method of claim 1, wherein the weight is set in advance by using a simulation or a field test for each of the transmission formats at a receiving side receiving the received signal.