KR20010048327A - Decoding apparatus and method of receiving data packet from bluetooth baseband - Google Patents

Abstract

PURPOSE: An apparatus for decoding a data packet received in a bluetooth baseband is provided to complete the decoding and to remove an unnecessary decoding, if errors are generated, so as to perform the decoding with low power. CONSTITUTION: An FEC(Forward Error Correction) decoder(10) performs a decoding relating to packet information. A de-whitening device(11) spreads decoding data outputted from the FEC decoder(10). A demultiplexer(12) switches the data outputted from the de-whitening device(11). An HEC(Header Error Check)(13) checks errors relating to header information among the data. A CRC(Cyclic Redundancy Check)(14) checks errors relating to payload information among the data. A controller(15) senses the errors in the decoding process and completes the decoding.

Description

Decoding apparatus and method of receiving data packet from bluetooth baseband

The present invention relates to a decoding apparatus and method, wherein a Bluetooth base for decoding data according to each packet by referring to a header and payload length of data packets received in a Bluetooth baseband requiring low power An apparatus and method for decoding a data packet received in a band.

Bluetooth refers to a standard that can transmit and receive data at high speed using a radio frequency without a physical cable for communication between various electronic devices. Currently, to access the Internet using a mobile communication terminal, a terminal with a data communication function, a laptop, and a separate cable connecting the two are required. However, when Bluetooth is used, data communication between devices is performed by wireless communication, and cable connection is not necessary for various devices such as digital cameras and printers with Bluetooth function.

Bluetooth 1.0 of the Bluetooth standard defines data transmission speed as 1Mbps and transmission distance as 10 ~ 100m. Therefore, compared to the Infrared Data Association (IrDA) that uses infrared rays, the communication distance is longer, and because the high radio frequency of 2.4 GHz is used, communication is possible even when there is an obstacle. In addition, Bluetooth consumes less than 100mW at 2.7V. IrDA is a clear advantage in portable devices that need to save power because of the battery's limit of 150mW.

Bluetooth is a proximity wireless data communication standard proposed to transmit and receive data at high speed by using radio frequency (RF) without a physical cable in various electromagnetic periods, and employs voice coding method CVSD (Continuous Variable Slope Delta Modulation) It has the advantage that it is possible to transmit not only text data but also voice everywhere.

In order to communicate between devices operating in such a Bluetooth communication environment, connection work must be preceded. This connection work involves matching RF synchronization, establishing a link between link managers provided in a device to communicate, and a channel. It is necessary to go through the setting process to send and receive text data, voice, and the like.

Despite these advantages, Bluetooth systems require lower power consumption in view of their potential for use in portable devices such as mobile terminals.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide an apparatus for decoding a data packet received in a Bluetooth baseband that is efficient at low power by terminating the decoding and removing unnecessary decoding when an error occurs in decoding the received data packet.

Another technical problem to be solved by the present invention is to provide a method for decoding a data packet received in a low power Bluetooth baseband by terminating the decoding and removing unnecessary decoding when an error occurs in decoding the received data packet. .

1 is a block diagram showing the configuration of an apparatus for decoding a data packet received in a Bluetooth baseband according to the present invention.

2 is a diagram illustrating a format of a general data packet.

3 shows the types of data packets.

4 is a flowchart illustrating an operation of a method of decoding a data packet received in a Bluetooth baseband according to the present invention.

5 is a decoding timing diagram when the FEC type of payload information is No FEC.

6 is a decoding timing diagram when the FEC type of payload information is 1/3 FEC.

7 is a decoding timing diagram when the FEC type of payload information is 2/3 FEC.

In order to solve the technical problem to be achieved by the present invention, a decoding apparatus of a data packet received in a Bluetooth baseband includes decoding means for decoding the input header and payload information; Error checking means for checking an error on the decoded data output from the decoding means; And control means for controlling the decoding means and the error checking means, and stopping the decoding of the decoding means when an error occurs as a result of the check of the error checking means.

According to another aspect of the present invention, there is provided a decoding method of a data packet received in a Bluetooth baseband, the method comprising: (a-1) decoding the input header information and stopping decoding when an error occurs; And (a-2) decoding the input payload information and stopping decoding when an error occurs.

Hereinafter, with reference to the accompanying drawings will be described in detail the present invention.

1 is a block diagram showing the configuration of an apparatus for decoding a data packet received in a Bluetooth baseband according to the present invention.

The apparatus shown in FIG. 1 includes a Forward Error Correction (FEC) decoding means 10 which decodes input packet information, and a de-spread which spreads the formatted decoded data output from the FEC decoding means 10. De-whitening means 11, demultiplexer 12 for switching data output from the de-whitening means 11, HEC (Header Error Check) for checking an error for header information among the de-whitening data Means 13, a cyclic redundancy check (CRC) means 14 for checking an error of payload information among de-whitening data, and controlling each device, and detecting an error when performing decoding to perform decoding. Control means 15 for stopping.

2 is a diagram illustrating a format of a general data packet.

3 shows the types of data packets.

4 is a flowchart illustrating an operation of a method of decoding a data packet received in a Bluetooth baseband according to the present invention.

The flowchart shown in FIG. 4 includes the steps of decoding the header information (40), determining whether an error has occurred in the header information (41), stopping decoding (42), and decoding the payload information (43). Determining whether an error has occurred as a result of checking the length of the payload information (44), stopping decoding (45), determining whether an error has occurred when performing CRC (46), Step 47, which requires retransmission.

5 is a decoding timing diagram when the FEC type of payload information is No FEC.

6 is a decoding timing diagram when the FEC type of payload information is 1/3 FEC.

7 is a decoding timing diagram when the FEC type of payload information is 2/3 FEC.

Next, the present invention will be described in detail with reference to FIGS. 1 to 7.

The reception of data in Bluetooth is performed in the order of RF → correlator (not shown) → FEC decoding → De-Whitening → HEC check, CRC check → decryption of payload data. The present invention describes an apparatus and method for decoding header and payload data from after receiving data after a correlator to before decryption.

The format of the data packet of the Bluetooth system is composed of an access code of 72 bits, a header of 54 bits and a payload as shown in FIG. In this case, the access code is a part performing synchronization for one packet of the entire data including a sync word, and since the access code is decoded in the correlator, in the present invention, after the access code, the header and payload data The decoding will be described.

The decoding order of the data is FEC decoding (1/3 iterative decoding) of the header and FEC decoding (No, 1/3, 2/3) of the payload according to the header type after de-whitening as shown in the block diagram of FIG. Perform whitening, HEC check for header, and CRC check for payload. At this time, the decoding of the payload is also started before the decoding of the header (FEC, de-whitening, HEC check) is finished. Therefore, by configuring the header decoding means and the payload decoding means, respectively, a separate buffer is not required.

After the correlator, the data (RX_PKT) input as a serial (1 bit) is separated into a header, payload header, and payload data, and outputted. The payload data is separated into audio (RX_VPL) and data (RX_DPL) and then output to a buffer (audio, data) (not shown) in the form of 8 bits.

The function of each block shown in FIG. 1 is as follows. The FEC decoding means 10 performs 1/3 Repeatition on the header and No, 1/3, 2/3 decoding on the payload. In the case of 1/3 FEC decoding, overlapping data is output among three input data. When FEC decoding 54 bits of header is 1/3 FEC decoding, 18 bits of header information (3 bits AM_ADDR, 4) are shown. Bit TYPE, 1 bit FLOW, 1 bit ARQN, 1 bit SEQN, 8 bit HEC).

In the case of 2/3 FEC decoding, 10 bits of data are output from 15 bits of input. In this case, in case of 2/3 decoding, 15 bits of input data must be stored in a register, an error position calculation must be performed, and output after correction (10 bits). Therefore, a delay from input to output of data occurs. . Therefore, the data input while outputting the corrected data must be buffered for data processing.

In order to solve this problem, two modules are used to continuously process payload data input from the correlator while one decoder processes the next data while the other decoder outputs the corrected data.

In case of 1/3 FEC decoding, one error can be detected and corrected, but in case of 2/3 decoding, detection and correction is possible when one error occurs, but only when two or more errors occur. Do.

After the FEC decoding is finished, the corrected data is de-whitened by the de-whitening means 11. The de-whitening means 11 is used for spreading, scrambled, the formatted data output from the FEC decoding means 10. That is, the data is transformed according to the channel situation. In the de-whitening process, the header and payload are sequentially processed from one seed.

After the de-whitening is finished, the data is divided into a header and a payload in the demultiplexer 12 and output to the HEC means 13 and the CRC means 14 under the control of the control means 15, respectively.

The HEC means 13 checks an error of the header information switched by the demultiplexer 12 and informs the control means 15 of the error if an error occurs. The control means 15 that detects an error in the header information stops the current decoding operation and saves the power.

The CRC means 14 checks the error of the payload information switched by the demultiplexer 12 and informs the control means 15 of the error if an error occurs. The control means 15 that detects an error in the payload information requests retransmission for the information in which the error has occurred.

The control means 15 functions to generate an enable signal and output a status for controlling the operation of each block. For example, the control signal is a signal such as decoding start / stop, buffer (audio, data) write enable, etc., and the status signal is a HEC / CRC error flag, FEC correction number, FEC error number, or the like. It may consist of a signal providing information.

The format of the packet received in Bluetooth is configured as shown in FIG. 2 and the decoding of the access code is performed in the correlator and the data of the header and payload are input to the decoding apparatus of the present invention. At this time, the type of packet used is configured as shown in the table shown in FIG. 3, and determines the FEC type and CRC to be performed on all packets except the ID packet, and whether to decode the payload data length in the payload header. do.

Processing of the input data is shown in the flowchart of FIG.

First, decoding of header information is performed (step 40). When decoding is performed, 1/3 FEC, de-whitening, and HEC on header information are performed.

If an error occurs as a result of decoding the header information, power is saved by stopping decoding (steps 41 and 42).

If no error occurs as a result of decoding the header information, the payload information is decoded (step 43). When decoding is performed, the FEC for the payload information is determined, decoded, and de-whitened by referring to the 4-bit type information of the header information decoded above.

During the decoding of the payload information, it is determined whether an error has occurred as a result of checking the payload length of the payload information (step 44). As shown in the table of FIG. 3, the payload rank according to the 4-bit type is determined. When the payload rank is checked and the maximum value is exceeded, it is determined that an error has occurred.

If an error occurs as a result of checking the payload length, the power supply is saved by stopping decoding (step 45).

After the payload decoding, the CRC result is checked to request retransmission of the information in case of an error (steps 46 and 47).

In addition, the AM_ADDR and the data buffer may be checked to stop decoding the payload data.

The decoding of the input data proceeds to the pipeline structure by the control signal generated as in the timing diagrams of FIGS. 5, 6, and 7. The input data is processed after being processed without a separate buffer and output.

5 and 6 illustrate a No FEC, 1/3 FEC decoding timing diagram. When the RX_FECST signal, which is a start signal for decoding header and payload information after the correlator, is output, 1/3 of the input header data is output. FEC is performed (FEC_HDOEN), and de-whitening is performed at the next clock (WH_EN). While the header information is decoded, the decoding of the payload information (FEC_PLOEN) is also started.

After 7-bit data is output after the de-whitening of the header information, the header type is decoded. The method of decoding payload data is determined using this type information. However, since the HEC is not completed, the decoding of the payload information is stopped when the error (HEC_EFLG) is determined at the time of performing the HEC (HEC_EN).

After decoding the packet type of the header (refer to the table in FIG. 3), if there is a payload, it is determined whether the payload rank is a predetermined number or a value in the payload header. It is possible to determine the rank after decoding the payload header (de-whitening output (8 or 16 bits) to the payload header). If the maximum value of the length is exceeded, set the length to the maximum value and output the status. When there is a CRC together with the decoding completion signal (CRC_EN), the CRC flag is output (CRC_EFLG) and the decoding is terminated (RX_FECEND).

FIG. 7 is a 2/3 FEC decoding timing diagram. When an RX_FECST signal, which is a start signal for decoding header and payload information, is output after a correlator, 1/3 FEC of the input header data is performed (FEC_HDOEN). Then, de-whitening is performed at the next clock (WH_EN).

While the header information is decoded, the decoding of the payload information (FEC_PLOEN) is also started. In the case of 2/3 FEC decoding, the 15-bit input payload data should be stored in a register, the position calculation of the error should be performed, and the output should be corrected after correction (10 bits). Will occur. Therefore, the data input while outputting the corrected data must be buffered for data processing.

To solve this problem, two modules are used (FEC_PLOEN1, FEC_PLOEN2) to allow one decoder to process the next data continuously while one decoder corrects and outputs the payload data input from the correlator. The description is the same as that of FIGS. 5 and 6.

In addition, decoding may be stopped by an external input. When AM_ADDR decoding is not data corresponding to itself, or when the data buffer cannot write data, decoding may be stopped.

The present invention is not limited to the above-described embodiments and can be modified by those skilled in the art within the spirit of the invention.

As described above, according to the present invention, the received data packet is decoded in a pipelined structure and decoded in-language in the internal structure, and the decoding is performed as much as the determined quantity, and decoding is automatically or manually performed when a reception error occurs. By stopping and reducing the decoding of unnecessary data, there is an effect that an efficient data packet decoding circuit can be implemented for a low power supply.

Claims (14)

Decoding means for performing decoding on the input header and payload information; Error checking means for checking an error on the decoded data output from the decoding means; And And control means for controlling the decoding means and the error checking means and stopping the decoding of the decoding means when an error occurs as a result of the check of the error checking means. The method of claim 1 wherein said decoding means And decoding the payload information before completion of decoding of the header information under the control of the control means. The method of claim 1 wherein said decoding means Header decoding means for decoding the header information; And And a payload decoding means for decoding the payload information. The method of claim 1, wherein the decoding means is further configured according to a decoding result of the header information. 1/3 decoding means for outputting overlapping one bit of data of three input data; And An apparatus for decoding a data packet received in a Bluetooth baseband, characterized in that it consists of 2/3 decoding means for outputting 10 bits of data 15 bits of the input data. 5. A method according to claim 4, wherein the 2/3 decoding means A device for decoding a data packet received in a Bluetooth baseband, characterized in that two modules are configured in parallel to be processed continuously without a data buffering process. The method of claim 1, wherein the error checking means First error checking means for checking an error of the decoded header information; And And second error checking means for checking an error of the decoded payload information. The method of claim 6, In the Bluetooth baseband so that the header decoding data of the decoding data of the decoding means further comprises switching means for switching the payload decoding data to the first error check means is output to the second error check means. A device for decoding a received data packet. The method of claim 6, wherein the control means And decoding the decoding means when the error occurs in the first error checking means or the second error checking means. The method of claim 1, wherein the control means The decoding device of the data packet received in the Bluetooth baseband, characterized in that the decoding is stopped when the transmission / reception of wrong data between the Bluetooth device. (a-1) decoding the input header information and stopping decoding if an error occurs; And (a-2) decoding the received payload information and stopping decoding when an error occurs. 10. The method of claim 9, wherein the decoding of the payload information is started before the decoding of the header information is completed. The method of claim 9, wherein step (a-2) Stopping decoding when an error occurs as a result of checking the rank of the payload information from the decoding result of the header information (b-1); and (B-2) requesting retransmission of the error information when an error occurs as a result of the CRC check of the payload information from the decoding result of the header information. Method of decoding. The method of claim 11, wherein step (b-1) And an error occurs when the length of the payload information exceeds a maximum value. The method of claim 10, (a-3) A method of decoding a data packet received in a Bluetooth baseband, further comprising the step of stopping decoding when wrong data transmission / reception occurs between the Bluetooth devices.