KR100401189B1 - Apparatus and method for transmitting control command in mobile communication system - Google Patents

Abstract

PURPOSE: An apparatus and a method for transmitting a control command in a mobile communication system are provided to transmit the control command using code difference between channels. CONSTITUTION: A traffic data generator(211) generates traffic data. A power control bit generator(216) generates a control command in a control command period. An adder(217) exclusively and logically adds the traffic data and the control command, and outputs the added data. The first channel transmitter(221) exclusively and logically adds the traffic data, the first channel PN(Pseudo Noise) sequence and an orthogonal code, generates a band spreading signal, and transmits the band spreading signal to the first channel. The second channel transmitter(222) exclusively and logically adds the output of the adder(217), the second channel PN sequence and the orthogonal code, generates a band spreading signal, and transmits the band spreading signal to the second channel.

Description

Apparatus and method for transmitting control command in mobile communication system

The present invention relates to an apparatus and a method for transmitting a control command of a mobile communication system, and more particularly, to an apparatus and a method for transmitting a control command using a code difference between channels.

In a transmission device of a code division multiple access method (hereinafter referred to as CDMA), a mobile communication system transmits a signal using a source coder and a channel coder, spreads the spectrum, and transmits the received signal. The apparatus has a configuration in which the despread signal is spread after band despreading. At this time, the transmitting device inserts a control command in the data to be transmitted and transmits the same. The control command may be a power control command, a transmission control command, or the like.

1 illustrates an example of an apparatus for transmitting a power control command in a conventional mobile communication system.

Referring to FIG. 1, the traffic data generator 111 outputs data to be transmitted through a traffic channel. A long code generator 115 generates a long code which is an encryption code of the traffic data. In IS-95, the long code has a transmission rate of 64 times the traffic data. The first decimator 116 decimates the long code rate at 1:64 to match the data rate of the traffic data. An adder 112 adds and outputs the first decimated long code and the traffic data. The signal output from the adder 112 is traffic data to which the traffic data to be transmitted is added and the date-measured long code is added. The second decimator 117 decimates the first decimated long code at 1:24 to match the transmission rate of the power control command. The power control bit generator 113 generates a power control bit. The multiplexer 114 inputs the output of the power control bit generator 113 and the output of the adder 112 and selectively outputs traffic data or power control bits by the second decimating output. That is, the multiplexer 114 inserts and outputs a power control bit into the traffic data in the output period of the second decimator 117. The position to be inserted is determined using the long sign to average the interference to other channels.

The Walsh orthogonal code generator 118 generates a Walsh orthogonal code for channel classification of the traffic data. The adder 119 adds and outputs the Walsh orthogonal code to the output of the multiplexer 114. The I channel pilot PN sequence generator 120 and the Q channel pilot PN sequence generator 121 each generate a PN sequence of a corresponding phase channel. The adder 122 adds the output of the adder 119 and the output of the I-channel PN sequence generator 120 to generate spread data of the I-channel. The adder 123 adds the output of the adder 119 and the output of the Q channel PN sequence generator 121 to generate spread data of the Q channel. The baseband filters 124 and 125 filter out the signals of the spread spectrum I and Q channels output from the adders 122 and 123, respectively, and output them to the baseband. Oscillator 126 generates a local frequency. The I-channel mixer 128 mixes and outputs the output of the baseband filter 124 and the output frequency of the oscillator 126. A phase shifter 127 shifts the output of the oscillator 126 by π / 2 and outputs it. The Q-channel mixer 129 mixes and outputs the output of the baseband filter 125 and the output of the phase shifter 127. The adder 130 adds and outputs the outputs of the I channel mixer 128 and the Q channel mixer 129.

In FIG. 1, the adders 112, 119, 122, and 123 perform an exclusive logical sum operation on signals input as logical adders. Here, the exclusive OR operation performs an operation of outputting 1 when the input signals are different and outputting 0 when the input signals are the same. In the mobile communication system having the above configuration, the conventional control command transmission method transmits a value of "+1" and "-1" according to a command to be transmitted. In order to process such a control command quickly, the content of the command must be detected before channel decoding. That is, control commands that need to be processed quickly are transmitted without channel coding at the transmitting side, and the content of the control command is determined before the channel decoding at the receiving side, and the system is adjusted to the corresponding command. Therefore, an error may occur due to the channel environment because the data is transmitted without channel coding. To overcome this error, these bits are sent using a relatively higher power than other bits. This causes bad results in interference sensitive systems, such as CDMA systems, because it interferes strongly with the other party. In addition, in case of BPSK data modulation such as IS-95, the sender creates a deliberate error due to puncturing and the error is recovered through the channel decoder.

Accordingly, an object of the present invention is to provide an apparatus and method for transmitting control command information while reducing interference to traffic data in a transmission apparatus of a mobile communication system.

Another object of the present invention is to provide an apparatus and method for transmitting a control command by using a difference between a position at which control command information of I and Q channels is inserted in a transmitting apparatus of a mobile communication system.

It is still another object of the present invention to provide an apparatus and method for transmitting a control command while reducing the effect of intentional error caused by puncturing in a transmission apparatus of a mobile communication system using a BPSK modulation scheme.

It is still another object of the present invention to provide an apparatus and a method for transmitting a known bit and transmitting a control command using a difference from the bit in a transmitter of a mobile communication system using a QPSK modulation scheme.

In order to achieve the above object, a control command transmission apparatus of a mobile communication system transmitter of the present invention transmits a control command using the code difference between the I channel and the Q channel when spreading and transmitting traffic data to the I channel and the Q channel. The control command may be inserted and transmitted at a transmission rate set in a specific channel among the phase channels for extraction.

1 is a diagram illustrating a configuration of an apparatus for transmitting a control command in a conventional mobile communication system.

2 is a diagram illustrating a configuration of an apparatus for transmitting a control command in a mobile communication system according to a first embodiment of the present invention.

3 is a diagram illustrating a configuration of an apparatus for transmitting a control command in a mobile communication system according to a second embodiment of the present invention.

2 is a block diagram of a first embodiment in which a control command is transmitted using a code difference between an I channel and a Q channel in a mobile communication system according to an embodiment of the present invention.

Referring to FIG. 2, the traffic data generator 211 outputs data to be transmitted through a traffic channel. The long code generator 213 generates a long code which is an encryption code of the traffic data. In IS-95, the long code has a transmission rate of 64 times the traffic data. The first decimator 214 decimates the long code at 1:64 to match the data rate of the traffic data. The adder 212 adds and outputs the first decimated long code and the traffic data. Traffic data output from the adder 212 and traffic data to which a long code is added are added. The second decimator 215 decimates the first decimated long code at 1:24 to match the transmission rate of the power control command. The power control bit generator 216 generates a power control bit corresponding to a control signal according to a power intensity measured by an external power meter (eg, an RSSI detector), and controls the power by the output of the second decimator 215. Output a bit. That is, the power control bit is output at the time point of output by the second dating signal. The adder 217 adds the output of the adder 212 and the output of the power control bit generator 216 to generate a signal according to the sign difference between the two signals.

The Walsh orthogonal code generator 223 generates a Walsh orthogonal code for channel classification of the traffic data. I-channel PN sequence generator 218 and Q-channel PN sequence generator 219 generate PN sequences of corresponding phase channels, respectively. The adder 221 adds the traffic data output from the adder 212, the I-channel PN sequence output from the I-channel PN sequence generator 220, and the Walsh orthogonal code to generate the spread-spectrum traffic data of the I-channel. The adder 222 adds the traffic data output from the adder 217, the addition signal of the power control bit, the Q channel PN sequence output from the Q channel PN sequence generator 219, and the Walsh orthogonal code to add the spread spectrum traffic of the Q channel. Generate data. The baseband filters 224 and 225 filter out the signals of the spread spectrum I and Q channels output from the adders 221 and 222, respectively, and output them to the baseband. Oscillator 226 generates a local frequency. The I-channel mixer 228 mixes and outputs the output of the baseband filter 224 and the output frequency of the oscillator 226. A phase shifter 227 shifts the output of the oscillator 226 by π / 2 and outputs the shifted signal. The Q-channel mixer 229 mixes and outputs the output of the baseband filter 225 and the output of the phase shifter 227. The adder 230 adds and outputs the outputs of the I-channel mixer 228 and the Q-channel mixer 229.

In FIG. 2, adders 212, 217, 221, and 222 perform an exclusive logical sum operation as a logical adder.

The first embodiment of the present invention having the configuration as shown in FIG. 2 shows an example of transmitting a control command by using a code difference between symbols transmitted on an I channel and a Q channel when the control command is transmitted. It may be a power control command, a transmission control command, or the like.

2 illustrates a configuration of a transmitter for transmitting power control bits using a BPSK data modulation scheme. In the case of using the BPSK data modulation scheme as described above, when the I channel transmits original traffic data as it is and commands power increase to the Q channel only, “0” (“+1”) is set to “1” (“-1”). ) Or "1" ("-1") to "0" ("+1"). In this case, intentional bit error caused by puncturing can be alleviated because only I channel traffic data is available instead of Q channel traffic data only at the position where the control command is input at the receiving side.

3 is a block diagram of a second embodiment in which a control command is transmitted using a code difference between an I channel and a Q channel in a mobile communication system according to an embodiment of the present invention.

Referring to FIG. 3, the traffic data generator 311 outputs data to be transmitted through a traffic channel. The switch 312 switches the traffic data. The power control bit generator 313 generates a power control bit corresponding to a control signal according to the power intensity measured by an external power meter (eg, an RSSI detector). The multiplexer 314 inputs "0" data and traffic data switched by the switch 312, selects the "0" data at the time of power control bit output, and selects and outputs the traffic data in the remaining sections. Here, the "0" data is data for notifying that the control command is output, and the receiving side should know the "0" data. The multiplexer 315 inputs the traffic data switched by the switch 312 and the output of the power control bit generator 313, selectively outputs the power control bit at the time of transmitting the control command, and selectively outputs the traffic data in the remaining sections.

Walsh orthogonal code generator 323 generates a Walsh orthogonal code for channel classification of the traffic data. I-channel PN sequence generator 318 and Q-channel PN sequence generator 319 each generate a PN sequence of the corresponding phase channel. An adder 321 adds traffic data output from the multiplexer 314, an I channel PN sequence output from the I channel PN sequence generator 318, and a Walsh orthogonal code output from the Walsh orthogonal code generator 323, thereby spreading the bandwidth of the I channel. Generated traffic data. The adder 322 adds the traffic data output from the multiplexer 315, the addition signal of the power control bit, the Q channel PN sequence output from the Q channel PN sequence generator 319, and the Walsh orthogonal code, and then spreads the bandwidth of the Q channel. Generates traffic data. The baseband filters 324 and 325 filter out the signals of the spread spectrum I channel and Q channel output from the adders 321 and 322 to the baseband. Oscillator 326 generates a local frequency. The I-channel mixer 328 mixes the output of the baseband filter 324 and the output frequency of the oscillator 326. A phase shifter 327 shifts the output of the oscillator 326 by π / 2 and outputs the shifted signal. The Q channel mixer 329 mixes and outputs the output of the baseband filter 325 and the output of the phase shifter 327. The adder 330 adds and outputs the outputs of the I-channel mixer 328 and the Q-channel mixer 329.

In FIG. 3, the adders 321 and 322 perform an exclusive logical sum operation as a logical adder.

The second embodiment of the present invention having the configuration as shown in FIG. 3 illustrates an example of transmitting a control command by using a code difference between symbols transmitted on an I channel and a Q channel when the control command is transmitted. It may be a power control command, a transmission control command, or the like.

3 illustrates an example of transmitting a known bit in a transmitting apparatus of a mobile communication system using a QPSK modulation scheme and transmitting a control command using a difference from the bit. The control command assumes power control. have. In the case of the QPSK data modulation, a fixed value is assigned to a position where a control command is to be input to the I channel (“0” or “1”: illustrated as “0” in FIG. 3), and a power control bit generator 313 is provided to the Q channel. Assign "0" or "1" depending on the output of.

As described above in the first and second embodiments, when the transmitting side wants to transmit a control command to the receiving side, the command is set to "0" or "1" ("+1" or "-1"). Instead of transmitting directly, as shown in FIG. 3, the symbol difference between the I channel and the Q channel is used. As described above, in the case of the power control command, if the command to be transmitted is expressed as "0" or "1", when it is "1" (I channel ≠ Q channel) when exclusively ORing the values of the I channel and the Q channel, The transmission power is increased, and if "0" (I channel = Q channel), the transmission power is decreased. Also, when expressed as "+1" and "-1", if (I channel) X (Q channel) <0, transmission power is increased, and if (I channel) X (Q channel)> 0, transmission power is decreased. do. At this time, the control command may be transmitted in a maximum of four types such as "00", "01", "10", and "11" according to the value of the I channel and the Q channel. However, two cases of "same" and "different" are possible when information is to be transmitted due to a difference between values transmitted on the I channel and the Q channel.

As described above, in the case of modulating BPSK data such as IS-95 and punctually inserting and transmitting control commands, the information carried on the I and Q channels is destroyed by puncturing, but the same method as in the first embodiment. If a control command is sent to the receiver, no error occurs on the receiving side because the information is not destroyed on any one channel. In addition, QPSK data modulation requires puncturing both I and Q channels. However, in order to insert a control command in either one of the I channel or the Q channel, a puncture is performed to insert a specific value, and a specific value known to the receiver is inserted into the other channel. In this case, the receiving side can know which channel has inserted what value in the transmitting side, which enables the receiving side to perform synchronous demodulation. Therefore, in the embodiment of the present invention, since the control command is transmitted by the symbol difference between the I channel and the Q channel whether the data modulation is BPSK or QPSK, the transmission control command is made larger than other symbols at the position where the control command is inserted. There is no need, and this can reduce interference to other channels.

Claims (10)

In the control command transmission apparatus of a digital communication system transmitter, And transmitting the control command by using the code difference between the I channel and the Q channel when spreading and transmitting the transmission data to the I channel and the Q channel. In the control command transmission apparatus of a digital communication system transmitter using a BPSK modulation method, A generator for generating traffic data, A generator for generating a control command in a control command transmission period; An adder for outputting an exclusive OR of the traffic data and the control command; A first channel transmitter for generating a spread spectrum signal by exclusively ORing the traffic data, the first channel PN sequence, and an orthogonal code, and transmitting the first spreading signal to a first channel; And a second channel transmitter for generating a spread spectrum signal by exclusively ORing the output of the adder, the second channel PN sequence, and an orthogonal code, and transmitting the spread spectrum signal to a second channel. And a control command transmission apparatus using a code difference between the first channel and the second channel. The apparatus of claim 2, wherein the first channel is an I channel, the second channel is a Q channel, and the control command is a power control command. In the control command transmission apparatus of a digital communication system transmitter using a QPSK modulation method, A generator for generating traffic data, A generator for generating a control command, A switch for switching and outputting the traffic data; A first multiplexer for inputting output of the switch and specific data, selectively outputting the specific data at the time of transmitting a control command, and selectively outputting the traffic data output from the switch in the remaining sections; A second multiplexer configured to input outputs of the switch and the control command generator, selectively output the control command at the time of transmitting the control command, and selectively output the traffic data output from the switch in the remaining sections; A first channel transmitter for inputting an output of the first multiplexer, a first channel PN sequence, an orthogonal code, and performing an exclusive OR to generate a spread spectrum signal and transmitting the spread signal to the first channel; A second channel transmitter configured to input an output of the second multiplexer, a second channel PN sequence, and an orthogonal code, and generate an spread spectrum signal by performing an exclusive OR of these, and transmitting the spread spectrum signal to a second channel; And a control command transmission apparatus using a code difference between the first channel and the second channel. 5. The method of claim 4, wherein the first channel is an I channel, the second channel is a Q channel, the control command is a power control command, and the predetermined data is already known data indicating that the control data is transmitted. Control command transmission device of digital communication system. A method of transmitting a control command of a digital communication system transmitter for spreading and transmitting traffic data on an I channel and a Q channel, Digital control system transmitter characterized in that the control command is inserted and transmitted at a transmission rate set to only one of the phase channels so that the control command can be extracted using the code difference between the I channel and the Q channel at the time of transmitting the control command. Control command transmission method of. In the method of transmitting a control command of a transmitter of a digital communication system using a BPSK modulation scheme, and having a generator for generating traffic data and a generator for generating a control command in a control command transmission period, Exclusive ORing the traffic data and a control command; An exclusive OR of the traffic data, the first channel PN sequence, and an orthogonal code generates a spread spectrum signal, and then transmits the spread signal to the first channel, and simultaneously performs an exclusive OR of the exclusive OR signal, the second channel PN sequence, and an orthogonal code to generate a spread spectrum signal. After the transmission to the second channel, And a control command is transmitted using the code difference between the first channel and the second channel. 8. The method of claim 7, wherein the first channel is an I channel and the second channel is a Q channel. In the method of transmitting a control command of a transmitter of a digital communication system using a QPSK modulation scheme and having a generator for generating traffic data and a generator for generating a control command, Switching outputting the traffic data; Selecting and outputting the switching output traffic data to the first channel and the second channel at the time of traffic data transmission; After exclusively ORing the traffic data, the first channel PN sequence, and an orthogonal code, a spread spectrum signal is generated and transmitted through the first channel, and generating a spread spectrum signal by exclusively ORing the second channel PN sequence and orthogonal code. Transmitting to two channels, Selecting specific data to output to the first channel when the control command transitions to the time of transmitting the control command in the traffic transmission section, and outputting to the second channel by selecting the control command; By exclusively ORing the specific data of the first channel, the first channel PN sequence, and an orthogonal code, a spread spectrum signal is generated and transmitted to the first channel, and exclusively ORing the control command, the second channel PN sequence, orthogonal code, and band After the spread signal is generated and transmitted to the second channel, the process returns to the traffic data transmission process, And a control command transmission apparatus using a code difference between the first channel and the second channel. 10. The method of claim 9, wherein the first channel is an I channel, the second channel is a Q channel, and the control command is a power control command.

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