KR100230719B1 - Device for building transmit-channel of cdma system - Google Patents

Abstract

The present invention relates to a transmission channel establishment apparatus of a code division multiple access (CDMA) mobile communication system.

It includes a traffic channel having a data rate conversion function for maintaining a constant data rate of the information signal, and stabilizes the processing gain of the system by keeping the data rate of the information signal always constant before the channels are synthesized. In synthesizing each channel, the pilot channel signal is synthesized with the I-phase signal of the traffic channel, and the control channel signal is synthesized with the Q-phase signal of the traffic channel to balance signal constellation to improve the efficiency of the RF stage. Contribute to improvement

Description

Transmission channel establishment apparatus of code division multiple access mobile communication system

The present invention relates to an apparatus for establishing a transmission channel of a code division multiple access (CDMA) type mobile communication system. More specifically, the present invention relates to demultiplexing of a traffic channel. The present invention relates to a transmission channel establishing apparatus having a function of converting a data rate of an information signal into a size required by a system.

In general, in a CDMA mobile communication system, a signal transmission route from a base station to a mobile station is referred to as a "forward link". The forward link is composed of a plurality of transmission channels for transmitting information signals, system signals, call signals, and control signals for each mobile station. In order to transmit various channel signals to the mobile station via one transmission channel, the base station is provided with a transmission channel establishing apparatus for synthesizing various channel signals.

In the conventional forward link transmission channel construction apparatus, an information signal, a system signal, a call signal, and a control signal are input, and channel coding, interleaving, and symbol repetition by convolutional encoding are performed on each signal. After performing symbol repeating, each channel is synthesized in parallel by multiplexing or adding.

In general, the information signal of the channel signal serves as an important factor in determining the processing gain of the CDMA system.

However, in the conventional forward link transmission channel establishment apparatus, when the data rate of the information signal changes, the processing gain also changes correspondingly, and is applied when the information signal source is changed and the data rate does not meet the design specification. Not only can it be compatible with other services. Further, since the processing gain changes in accordance with the data rate of the information signal, there is a problem of efficiency deterioration such that the number of mobile stations accommodated in the mobile communication system is limited.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned technical problem, and by using demultiplexing before converting an information signal to a signal of another channel, the data rate of the information signal is converted to a constant size so that a stable processing gain is maintained. Its purpose is to provide a transmission channel establishing apparatus.

In addition, another object of the present invention is to combine the pilot channel signal with the I-phase signals of the multiple traffic channels and the control channel signal with the Q-phase signals of the multiple traffic channels so that all mobile stations in the same base station The present invention provides a transmission channel establishing apparatus that shares signal constellations in a balanced manner.

1A to 1E are block diagrams of respective channels of a transmission channel establishment apparatus of a code division multiple access mobile communication system according to an embodiment of the present invention.

In order to achieve the above object, the transmission channel establishment apparatus of the CDMA mobile communication system according to the present invention,

A pilot channel for generating a channel signal by multiplying a predetermined Walsh code and a pilot code by a system channel, a call channel, and all data "0",

A control channel for generating a channel signal by multiplying the control signal by a predetermined Walsh code and a pilot code;

An input means for channel coding an information signal to generate an I-phase signal and a Q-phase signal, adjust the data arrangement order of the I-phase signal and the Q-phase signal, and multiply the scrambled long code to output the output signal; Converts data rate of each of I and Q phase signals to the size required by the system, multiplies them by a predetermined Walsh code, and adds the same phase to each other to generate data rate converted I phase signal and Q phase signal. A plurality of traffic channels comprising means and output means for performing a baseband filtering process after multiplying each phase signal output from the data rate converting means by a pilot code; And

And channel combining means for synthesizing the I-phase signal and the pilot channel signal outputted from the plurality of traffic channels and synthesizing the Q-phase signal and the control channel signal outputted from the plurality of traffic channels.

The objects, features and advantages of this invention described above will become more apparent from the following detailed description of the embodiments with reference to the drawings.

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

For reference, in the embodiment of the present invention, a transmission channel establishing apparatus is disclosed assuming that it is used for the forward link, but may also be used for the reverse link.

FIG. 1A is a block diagram illustrating a pilot channel, FIG. 1B is a system channel, FIG. 1C is a call channel, FIG. 1D is a control channel, and FIG. 1E is a traffic channel in a transmission channel establishing apparatus according to an embodiment of the present invention. 1f is a block diagram showing the synthesis between each channel.

In the transmission channel establishing apparatus according to the present invention, there are a plurality of traffic channels in order to cover all users, which is illustrated in FIG. 1E for one of them.

First, referring to FIG. 1A, the pilot channel is composed of multipliers 11 and 13, a pilot code generator 12, and a baseband pass filter 14. In general, a pilot channel uses data of all zeros to find out the characteristics of a channel. That is, the data all '0' is used to change the environment between the transmitter and the receiver in the pilot channel does not have any information, unlike the system channel, call channel, traffic channel, and the like. Specifically, the pilot received from the receiver is transmitted to the pilot channel after multiplying the data of all zeros by a predetermined Walsh code (mostly Walsh code '0' is used) and the pilot code. The channel can be used to know the delay, attenuation and phase change of any channel.

All of these '0' data is input to the multiplier 11, multiplied by Walsh code 0, and then output to the multiplier 13. In the multiplier 13, the pilot code provided by the pilot code generator 12 is multiplied by the output of the multiplier 11,

A signal in which the Walsh code 0 and the pilot code are combined with data of all '0's is filtered by the baseband pass filter 14 to remove noise components included in the baseband. It is provided as a phase signal.

Referring to FIG. 1B, the system channel is convolutional encoder 21, block interleaver 22, symbol repeater 23, multiplier 24, 25, 27, 28, pilot code generator 26, baseband pass. It consists of the filters 29 and 30.

The system signal is input to the convolutional encoder 21, which convolutional encoder 21 channel codes the system signal to minimize the occurrence of random error in the system signal. The I-phase signal and the Q-phase signal having phase orthogonal characteristics are generated by the channel coding. The I-phase signal and the Q-phase signal are generated by channel coding independently by two generation polynomials.

The block interleaver 22 divides the I-phase signal and the Q-phase in order to disperse the burst error generated when the I-phase signal and the Q-phase signal generated by the convolutional encoder 21 pass through the transmission channel. Change the data order of the signals. The I and Q phase signals whose arrangement order is adjusted are output to the symbol repeater 23.

The symbol repeater 23 makes the length of each symbol constant by repeatedly arranging the predetermined number of symbols according to the lengths of the symbols included in the I and Q phase signals output from the block interleaver 22. The I and Q phase signals in which the symbols are arranged are output to the multipliers 24 and 25, respectively, and multiplied by the Walsh code S. Each phase signal multiplied by the Walsh code S is output to the multipliers 27 and 28, and the pilot code provided from the pilot code generator 26 by each multiplier 27 and 28 is multiplied.

The signals output from each of the multipliers 27 and 28 are provided to the pair of baseband filters 29 and 30 and subjected to filtering to remove noise included in the baseband. The filtered signal is provided to a modulation module (not shown) as I and Q phase signals.

Referring to FIG. 1C, the system channel includes convolutional encoder 31, block interleaver 32, symbol repeater 33, multiplier 34, 35, 37, 38, pilot code generator 36, baseband pass It consists of the filters 39 and 40.

As shown in FIG. 1C, the call channel is the same as the system channel except that the system channel and the input signal shown in FIG. 1B are call signals, and the Walsh code P is multiplied in the multipliers 34 and 35. Since the functions are the same, a detailed description thereof will be omitted.

The control channel is shown in FIG. 1D and consists of multipliers 41 and 43, a pilot code generator 42, and a baseband pass filter 44.

The control signal is multiplied by the Walsh code C by the multiplier 41, and the control signal multiplied by the Walsh code C is output to the multiplier 43. Multiplier 43 multiplies the pilot code provided by pilot code generator 42 with the output signal of multiplier 41 and outputs the resulting signal to baseband pass filter 44. The baseband pass filter 44 performs a filtering process to remove noise included in the baseband of the control signal obtained by combining the Walsh code C and the pilot code. Meanwhile, in the apparatus for establishing a transmission channel according to the embodiment of the present invention, control signals for all traffic channels are shared by one control channel.

1e shows a traffic channel.

Referring to FIG. 1E, an information signal is input to a convolutional encoder 51, and the convolutional encoder 51 channels the information signal in order to minimize occurrence of a random error in the information signal. Coding The I-phase signal and the Q-phase signal having phase orthogonal characteristics are generated by the channel coding. The I-phase signal and the Q-phase signal are generated by channel coding independently by two generation polynomials.

The block interleaver 52 divides the I-phase signal and the Q-phase to disperse the burst error generated when the I-phase signal and the Q-phase signal generated by the convolutional encoder 51 pass through the transmission channel. Change the data order of the signals. The I and Q phase signals whose arrangement order is adjusted are output to the multipliers 55 and 56, respectively.

The long code generator 53 generates a long code from a user code assigned to the mobile station, which is scrambled by a decimator 54. In each multiplier 55 and 56, the I and Q phase signals whose arrangement order is adjusted are multiplied by the logarithm long code.

The output signals of the multipliers 55 and 56 are output to the demultiplexer 57, and the demultiplexer 57 separates the input I and Q phase signals into block units. It depends on the transmission speed.

For example, when the signal in front of the demultiplexer 57 has a transmission rate of 32 kps per second (kilo symbols per second), and the information signal is required to have a speed of 16 kps, the demultiplexer 57 is connected to an I phase signal of 32 kps. Each Q-phase signal is separated into two channels with a transmission rate of 16ksps.

In the embodiment of the present invention, the number of channels to be separated is two, but the technical scope of the present invention is not limited thereto. If an I-phase signal and a Q-phase signal having a data rate of 64ksps are input to the demultiplexer 57, and a transmission rate of 16ksps is required, the data rate of four channels of 16ksps is determined by a demultiplexer having a 1x4 input / output pattern. Branches can also be designed to be separated into four channels. Such design changes will be apparent to those skilled in the art, and configurations using multiple demultiplexers are possible.

The phase signals whose data rates are converted by the demultiplexer 57 are output to the multipliers 58, 59 and 60, 61 for respective phases, and the Walsh codes T1 to T _N are multiplied, respectively. The output signals of the respective multipliers 58 to 61 are provided to the adder 62 and added for each phase. In this way, the I and Q phase signals obtained by combining the Walsh codes are obtained, and each signal is multiplied by the pilot code from the pilot code generator 63 by the multipliers 64 and 65. Subsequently, each phase signal to which the pilot code is synthesized is subjected to filtering processing to remove noise included in the baseband by the baseband pass filters 66 and 67.

As described above, in the traffic channel, the processing gain of the system can be stabilized by keeping the data rate of the information signal constant by demultiplexing regardless of the data rate of the input information signal. As a result, a stable processing gain can be secured regardless of the data rate of the information signal, thereby improving the efficiency of the system.

Meanwhile, in FIG. 1F, logic for synthesizing respective channels is shown.

In FIG. 1F, all-traffic channel 71 is formed by combining a plurality of traffic channels shown in FIG. 1E and covers all mobile stations assigned to a unit base station.

The signal output from the pilot channel described above is added by the adder 72 together with the I phase signal provided from the all traffic channel 71, and the signal output from the control channel is provided from the all traffic channel 71. It is added by the adder 73 together with the Q phase signal. The signals synthesized by the adders 72 and 73 are output to the baseband filters 74 and 75, where filtering is performed to remove noise components included in the baseband.

The signal filtered by each baseband filter 74, 75 is provided to a modulation module (not shown).

When the channel is synthesized as described above, the signal constellation is balanced by synthesizing the pilot channel signal and the control signal to the I and Q phase signals of all the traffic channels 71, respectively, which is followed by radio frequency (RF). Improve the efficiency at the stage.

The apparatus for establishing a transmission channel according to the present invention includes a traffic channel having a data rate conversion function for maintaining a constant data rate of an information signal. That is, the data rate of the information signal is kept constant before the channels are synthesized, thereby stabilizing the processing gain of the system. Also, in synthesizing each channel, a signal constellation balance is achieved by synthesizing a pilot channel signal with an I-phase signal of a traffic channel and synthesizing a control channel signal with a Q phase signal of a traffic channel. Contribute to improving efficiency.

Although this invention has been described with reference to the most practical and preferred embodiments, the invention is not limited to the embodiments disclosed above, but also includes various modifications and equivalents which fall within the scope of the following claims.

Claims (4)

A CDMA mobile communication system comprising a system channel, a call channel, and a pilot channel for generating a channel signal by multiplying a predetermined Walsh code and a pilot code by data all "0", wherein the control signal is assigned a predetermined Walsh code and a pilot code. A control channel for multiplying to generate a channel signal; An input means for channel coding an information signal to generate an I-phase signal and a Q-phase signal, adjust the data arrangement order of the I-phase signal and the Q-phase signal, and multiply the scrambled long code to output the output signal; Converts data rate of each of I and Q phase signals to the size required by the system, multiplies a predetermined Walsh code, and adds the same phases to each other to generate data rate converted I phase signal and Q phase signal. A plurality of traffic channels comprising means and output means for performing a baseband filtering process after multiplying each phase signal output from the data rate converting means by a pilot code; And channel synthesis means for synthesizing the I-phase signals and the pilot channel signals output from the plurality of traffic channels and synthesizing the Q-phase signals and control channel signals output from the plurality of traffic channels. Transmission channel establishment apparatus. 2. The apparatus of claim 1, wherein the data rate converting means of the traffic channel comprises: a demultiplexer for separating each of the I and Q phase signals outputted from the input means into at least two channels in predetermined block units; A plurality of multipliers for multiplying a signal output from the demultiplexer by a predetermined Walsh code; And an adder for adding I and Q phase signals whose data rates are converted by adding the same phases among the output signals of the multipliers, respectively. 3. The apparatus of claim 1 or 2, wherein the channel synthesizing means comprises: a first adder which adds I-phase signals output from the plurality of traffic channels and signals of the pilot channel; A second adder for adding a Q phase signal output from the plurality of traffic channels and a signal of the control channel; And a pair of baseband filters for baseband filtering the output signals of the first and second adders. The apparatus of claim 1, wherein the control signals for all of the plurality of traffic channels share the one control channel.

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