JP3581049B2 - Frame configuration method, frame configuration device, frame configuration, transmission power control method, and wireless station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize reduction of transmission power and increase of capacity and to secure the required quality of control bits themselves by setting up the electric energy of the control bits to a value capable of minimizing the required transmission power of individual channels. SOLUTION: The method for constituting frames in a CDMA mobile communication system is provided with a step for determining the optimum electric energy of transmission power, a step for setting up the transmission power of control bits equal to that of data bits, a step for setting up the transmission power of the control bits to the optimum electric energy by adjusting the number of control bits, and a step for setting up the transmission power of control bits to the optimum electric energy by offsetting the transmission power of data bits. The optimum electric energy E0 is the electric energy of control bits capable of minimizing the required transmission power of the whole individual channel.

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a frame configuration method, a frame configuration device using the method, and Frame configuration In particular, a transmission power control method, a transmission power control apparatus using the method, and a radio station About .
[0002]
More specifically, the present invention relates to a mobile communication system using CDMA (Code Division Multiple Access) for performing multiple access using spread spectrum, in which a control bit is set to a data bit in an individual channel for controlling transmission power. When the measurement of the desired signal reception signal power to interference power ratio (SIR) or the like for transmission power control is performed using the control bits, the control bits and the data bits are set to the optimal power amount distribution. The present invention relates to a frame configuration technology that can be used.
[0003]
[Prior art]
FIG. 1 shows a state of interference from another mobile station on an uplink (mobile station to base station) line. When the mobile station MS1 near the base station BS1 and the mobile stations MS2 and MS3 far from each other perform communication at the same time, the base station BS1 receives a large signal power from the mobile station MS1 near the base station, whereas the base station BS1 receives a large signal power. Of the mobile stations MS2 and MS3. Therefore, the communication between the distant mobile stations MS2 and MS3 and the base station BS1 receives interference from the nearby mobile station MS1, and the characteristics are greatly deteriorated.
[0004]
Also, in the downlink (from base station to mobile station), distant mobile stations are more affected by noise, and especially in the cellular system, more interference from base stations of other cells is received. Will do.
[0005]
As a technique for solving these problems, transmission power control has been conventionally studied. In the transmission power control, control is performed so that the reception power received by the reception station or the desired signal reception signal power to interference power ratio (SIR) determined from the reception power is constant regardless of the location of the mobile station. In this way, uniform communication quality can be obtained within the service area. Since the signal power of another communicator is an interference signal, it is necessary to perform transmission power control so that the signal power does not become much larger than the signal power of the own channel. For the uplink channel, each mobile station needs to perform transmission power control so that the reception SIR from each mobile station becomes constant at the reception input of the base station.
[0006]
Conventionally, transmission power control of a mobile station in a base station is performed, for example, as follows.
[0007]
(1) The base station sets a required SIR corresponding to a satisfactory reception quality of a signal from a certain mobile station.
[0008]
(2) The base station measures the reception SIR of the signal sent from the mobile station.
[0009]
(3) The base station determines whether the reception SIR of a signal from the corresponding mobile station is larger or smaller than the required SIR.
[0010]
(4) The base station periodically inserts a transmission power control bit corresponding to the determination result into the frame of the downlink signal, and increases the transmission power to the mobile station by the transmission power control bit. , Specify lowering.
[0011]
In addition, the same process is performed for the downlink channel as in the case of the uplink channel. In particular,
(1) The mobile station sets a required SIR corresponding to a satisfactory reception quality of a signal from the base station.
[0012]
(2) The mobile station measures the reception SIR of the signal transmitted from the base station.
[0013]
(3) The mobile station determines whether the received SIR of the signal from the corresponding base station is larger or smaller than the required SIR.
[0014]
(4) The mobile station periodically inserts a transmission power control bit corresponding to the determination result into the frame of the uplink signal, and increases the transmission power to the base station by the transmission power control bit. , Specify lowering.
[0015]
FIG. 2 shows an example of a frame structure of an individual channel in a CDMA mobile communication system according to the related art.
[0016]
As shown in FIG. 2, in the dedicated channel 20, a control bit portion 22 indicating control information such as a transmission power control bit and a rate identification bit is usually arranged together with a data bit portion 24 indicating user information. The control bit portion 22 and the data bit portion 24 are collectively called a frame.
[0017]
FIG. 3 shows the relationship between the power amount of the control bits and the bit error rate of the control bits.
[0018]
In FIG. 3, the power amount in one frame that satisfies the required quality of the control bits is E ₁ Is shown. In the related art, when a control bit is allocated in a frame, the control bit is arranged in a dedicated channel with an amount of power that satisfies the required quality of the control bit itself (for example, E in FIG. 3). ₁ ).
[0019]
[Problems to be solved by the invention]
The control bit is always used for transmission, unlike the data bit portion in which the number of transmission bits and the transmission power can change sequentially with the change in the speed of the user data, and thus may be used for SIR measurement for transmission power control.
[0020]
FIG. 4 shows the relationship between the amount of control bit power per frame and the required transmission power of an individual channel when SIR measurement is performed using control bits. Here, the required transmission power of the dedicated channel refers to a transmission power obtained by combining the control bits and the data bits so as to satisfy the required quality of the data bits.
[0021]
As shown in FIG. 4, when the control bits are used for SIR measurement, as the power amount of the control bits is increased, the SIR measurement accuracy is improved and the transmission power control can be performed with high accuracy. Required transmission power, but the power amount of control bits To If it is increased, the transmission power of the entire individual channel will increase.
[0022]
Therefore, there is an optimum point of the power amount of the control bit so as to minimize the required transmission power of the dedicated channel. For example, in FIG. ₀ Is the optimal amount of power.
[0023]
However, conventionally, as described above, the control bit is a power amount that satisfies the required quality of the control bit itself (for example, E in FIG. 3). ₁ ), The amount of power is changed to E in FIG. ₀ If it is smaller than this, there is a problem that the accuracy of the SIR measurement deteriorates, causing an increase in transmission power and a deterioration in capacity.
[0024]
Therefore, the present invention provides a frame configuration for making the control bits and the data bits have an optimal power amount distribution by matching the power amount of the control bits to the point where the required transmission power of the dedicated channel is minimized. It is an object of the present invention to reduce the power and increase the capacity and to make the quality of the control bit itself higher than required quality.
[0025]
[Means for Solving the Problems]
To achieve the above object, an invention according to claim 1 is a method for configuring a frame in a CDMA mobile communication system, comprising: part The optimal amount of power to allocate to Configuration The step of Included in control bits Control bit transmit power Included in data bit part Equalizing the transmission power of the data bits; part By adjusting the number of bits of the control bits, Assign to part Setting a transmission power amount to the optimum power amount.
[0026]
The invention according to claim 2 is a frame configuration method in a CDMA mobile communication system, wherein a control bit part The optimal amount of power to allocate to Configuration Steps to Included in data bit part Data bit transmit power Independently adjusting the transmission power of the control bits included in the control bit portion The control bit Assign to part Setting a transmission power amount to the optimum power amount.
[0027]
According to a third aspect of the present invention, in the frame configuration method according to the first or second aspect, the control bit part The optimal power amount is a power amount that minimizes the required transmission power of the entire dedicated channel.
[0028]
The invention according to claim 4 is a frame configuration device in a CDMA mobile communication system, wherein a control bit part The optimal amount of power to allocate to Configuration Means for Included in control bits Control bit transmit power Included in data bit part Means for equalizing the transmission power of the data bits, and said control bits part By adjusting the number of bits of the control bits, Assign to part Means for setting a transmission power amount to the optimum power amount.
[0029]
The invention according to claim 5 is a frame configuration device in a CDMA mobile communication system, wherein a control bit part The optimal amount of power to allocate to Configuration Means to Included in data bit part Data bit transmit power Independently adjusting the transmission power of the control bits included in the control bit portion The control bit Assign to part Means for setting a transmission power amount to the optimum power amount.
[0030]
According to a sixth aspect of the present invention, in the frame configuration device according to the fourth or fifth aspect, the control bit part The optimal power amount is a power amount that minimizes the required transmission power of the entire dedicated channel.
[0031]
According to a seventh aspect of the present invention, there is provided a CDMA mobile communication system. Frame configuration And Included in control bits Data bits having a transmission power equal to the transmission power of the control bits Data bit part including And the above-described control in which the number of bits is adjusted so as to obtain an optimal power amount.
bit part And characterized in that:
[0032]
The invention according to claim 8 is for a CDMA mobile communication system. Frame configuration And Included in data bit part Data bit transmit power Independently adjusts the transmission power of the control bits included in the control bits The control bit that makes the transmission power amount the optimum power amount part It is characterized by having.
[0033]
The invention according to claim 9 is the invention according to claim 7 or claim 8. Frame configuration In the above, the control bit part The optimal power amount is a power amount that minimizes the required transmission power of the entire dedicated channel.
[0034]
The invention according to claim 10 is the invention according to any one of claims 7 to 9. Frame configuration In the above, the control bit part Is characterized by including a bit sequence corresponding to a result of comparison between reception quality and required quality.
[0035]
The invention according to claim 11 is the invention according to any one of claims 7 to 10. Frame configuration And said Frame configuration Is the transmission signal Transmitted as It is characterized by the following.
[0036]
13. The transmission power control method according to claim 12, wherein the first wireless station measures the reception quality of a signal transmitted by the second wireless station, and the reception measured by the measuring step. Comparing the quality with the required quality and the comparison result of the comparing step
Generating a corresponding bit sequence; and controlling bits including the bit sequence generated by the step of generating the bit sequence. part Generating the control bits.
G part The optimal amount of power to allocate to Configuration The step of Included in control bits Control bit transmit power Included in data bit part Equalizing the transmission power of the data bits; part By adjusting the number of bits of the control bits, Assign to part Setting the transmission power amount to the optimum power amount; and setting the control bit determined as the optimum power amount by the step of setting the optimum power amount. part Composing a frame comprising: transmitting the frame to the second wireless station; and
A second wireless station comprising: receiving the frame transmitted by the transmitting step; and adjusting transmission power based on the bit sequence included in the frame received by the receiving step. It is characterized by the following.
[0037]
The invention according to claim 13 is a transmission power control method, wherein the first wireless station measures the reception quality of the signal transmitted by the second wireless station, and the reception measured by the measuring step Comparing the quality with the required quality and the comparison result of the comparing step
Generating a corresponding bit sequence; and controlling bits including the bit sequence generated by the step of generating the bit sequence. part And the control bits part The optimal amount of power to allocate to Configuration Steps to Included in data bit part Data bit transmit power Independently adjusting the transmission power of the control bits included in the control bit portion The control bit Assign to part Setting the transmission power amount to the optimum power amount; and setting the control bit determined as the optimum power amount by the step of setting the optimum power amount. part Constructing a frame comprising: transmitting the frame to the second wireless station; and, at the second wireless station, receiving the frame transmitted by the transmitting step; Adjusting the transmission power based on the bit sequence included in the frame received in the receiving step.
[0038]
According to a fourteenth aspect of the present invention, in the transmission power control method according to the twelfth or thirteenth aspect, the control bit part The optimal power amount is a power amount that minimizes the required transmission power of the entire dedicated channel.
[0039]
The invention according to claim 15 is a radio station, comprising: means for measuring reception quality of a received signal; means for comparing reception quality measured by the measurement means with required quality; and means for comparing Means for generating a bit sequence corresponding to the comparison result, and means for generating the bit sequence.
Control bits containing said bit sequence generated by a stage part And the control bit part The optimal amount of power to allocate to Configuration Means for Included in control bits Control bit transmit power Included in data bit part Means for equalizing the transmission power of the data bits, and said control bits part By adjusting the number of bits of the control bits, Assign to part Means for setting the transmission power amount to the optimum power amount; and the control bit set to the optimum power amount by the means for setting the optimum power amount. part And a means for transmitting the frame.
[0040]
The invention according to claim 16 is a radio station, comprising: means for measuring reception quality of a received signal; means for comparing reception quality measured by the measurement means with required quality; and means for comparing Means for generating a bit sequence corresponding to the comparison result, and means for generating the bit sequence.
Control bits containing said bit sequence generated by a stage part And the control bit part The optimal amount of power to allocate to Configuration Means to Included in data bit part Data bit transmit power Independently adjusting the transmission power of the control bits included in the control bit portion The control bit Assign to part Means for setting the transmission power amount to the optimum power amount; and the control bit set to the optimum power amount by the means for setting the optimum power amount. part And a means for transmitting the frame.
[0041]
According to a seventeenth aspect of the present invention, in the wireless station according to the fifteenth or sixteenth aspect, the control bit part The optimal power amount is a power amount that minimizes the required transmission power of the entire dedicated channel.
[0042]
The invention according to claim 18 is a wireless station, wherein the wireless station according to any one of claims 15 to 17 receives the frame transmitted by the frame transmitting means, Means for adjusting transmission power based on the bit sequence included in the frame received by the means for receiving the frame.
[0043]
An invention according to claim 19 is a transmission power control method, wherein a control bit is transmitted to a first radio station. part The optimal amount of power to allocate to Configuration The step of Included in control bits Control bit transmit power Included in data bit part Equalizing the transmission power of the data bits; part By adjusting the number of bits of the control bits, Assign to part Setting the transmission power amount to the optimum power amount; and setting the control bit determined as the optimum power amount by the step of setting the optimum power amount. part Constructing a frame including: transmitting the frame to a second wireless station; and measuring, at the second wireless station, the reception quality of the signal transmitted by the first wireless station; Comparing the reception quality measured by the measuring step with required quality, generating a bit sequence corresponding to a comparison result of the comparing step, and generating the bit sequence by generating the bit sequence. To the first radio station.
Receiving the bit sequence transmitted by the second radio station in the first radio station, and adjusting transmission power based on the bit sequence received in the receiving step. It is characterized by having.
[0044]
The invention according to claim 20 is a transmission power control method, wherein a control bit is transmitted in a first wireless station. part The optimal amount of power to allocate to Configuration Steps to Included in data bit part Data bit transmit power Independently adjusting the transmission power of the control bits included in the control bit portion The control bit Assign to part Setting the transmission power amount to the optimum power amount; and setting the control bit determined as the optimum power amount by the step of setting the optimum power amount. part Constructing a frame including: transmitting the frame to a second wireless station; and measuring, at the second wireless station, the reception quality of the signal transmitted by the first wireless station; Comparing the reception quality measured by the measuring step with required quality, generating a bit sequence corresponding to a comparison result of the comparing step, and generating the bit sequence by generating the bit sequence. Transmitting to the first wireless station; and transmitting the second wireless station to the first wireless station.
Receiving the bit sequence, and adjusting transmission power based on the bit sequence received in the receiving step.
[0045]
According to a twenty-first aspect of the present invention, in the transmission power control method according to the twelfth or twentieth aspect, the step of measuring the reception quality comprises: part It is characterized by using at least a part of the measurement.
[0046]
The invention according to claim 22 is the transmission power control method according to claim 19 or 20, wherein the step of measuring the reception quality comprises the step of transmitting the control bit transmitted by the first wireless station. part And at least one data bit transmitted by the first wireless station. part It is characterized by using at least a part of the measurement.
[0047]
An invention according to claim 23 is the transmission power control method according to any one of claims 19 to 22, wherein the control bit part The optimal power amount is a power amount that minimizes the required transmission power of the entire dedicated channel.
[0048]
According to a twenty-fourth aspect of the present invention, a wireless station includes the frame configuration device according to any one of the fourth to sixth aspects, and means for transmitting a frame configured by the frame configuration device. Features.
[0049]
An invention according to claim 25 is a wireless station, wherein the wireless station according to claim 24 receives the frame transmitted by the frame transmitting means, and the frame received by the frame receiving means. Means for measuring the reception quality of the data, means for comparing the reception quality measured by the means for measurement with required quality, means for generating a bit sequence corresponding to a comparison result of the means for comparing, and generation of the bit sequence Means for transmitting said bit sequence generated by said means.
[0050]
According to a twenty-sixth aspect of the present invention, in the wireless station according to the twenty-fifth aspect, the means for measuring the reception quality comprises the control bit transmitted by the first wireless station. part It is characterized by using at least a part of the measurement.
[0051]
The invention according to claim 27, wherein in the wireless station according to claim 25, the means for measuring the reception quality comprises the control bit transmitted by the first wireless station. part And at least one data bit transmitted by the first wireless station. part It is characterized by using at least a part of the measurement.
[0052]
According to the present invention, by matching the power amount of the control bits to the point where the required transmission power of the dedicated channel is minimized, the control bit and the data bits have a frame configuration that optimizes the power amount distribution, The transmission power can be reduced and the capacity can be increased, and the quality of the control bits can be equal to or higher than the required quality.
[0053]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0054]
Here, a transmission power control technique for controlling transmission power based on control bits in a CDMA mobile communication system will be described as an example. However, the present invention is not limited to such an embodiment, and other CDMA mobile communication systems may be used. Obviously, it can be used in a frame configuration technique in a communication system as well.
[0055]
FIG. 5 is a block diagram showing an example of the configuration of a CDMA mobile station according to the present invention.
[0056]
The mobile station 100 is roughly composed of mobile station receiving blocks 102 to 126 and mobile station transmitting blocks 130 to 140.
[0057]
First, the mobile station receiving unit blocks 102 to 126 will be described. A downlink signal transmitted from the base station 200 and received by the mobile station is converted into an RF (high frequency) unit / down converter 102 for performing high frequency demodulation and the like, an AGC (automatic gain control). Control) The signal enters the despreading unit 108 through the amplifier 104 and the quadrature detector 106. The despreading unit 108 despreads the signal spread by the pseudo noise (PN) code. The output signal of despreading section 108 is supplied to demodulator / rake combining section 110, timing generating section 114, desired signal power detecting section 116, and interference signal power detecting section 122, respectively.
[0058]
The demodulator / rake combiner 110 performs demodulation processing such as inverse transform of a Walsh-transformed signal and combines signals received from the multipath at a plurality of timings by a maximum ratio combining method or the like. The frame separation unit 112 separates and extracts the transmission power control bits from the symbol sequence of the downlink signal thus combined. The timing generation unit 114 detects a pilot signal of a downlink signal, generates a timing signal for synchronization, and supplies the timing signal to the desired wave signal power detection unit 116 and the interference signal power detection unit 122. Desired-wave signal power detection section 116 measures the desired-wave received signal power (level) from the base station. The desired signal reception signal power (level) is sent to reception SIR calculation section 124.
[0059]
The transmission power determination unit 120 receives the transmission power control bits from the frame separation unit 112, generates instantaneous transmission power control information based on the transmission power control bits, and outputs the information to the amplitude adjustment unit 135.
[0060]
The creation of the instantaneous transmission power control information is performed, for example, by any of the following methods.
[0061]
1) When the bit sequence included in the received transmission power control bits is “1”, instantaneous transmission power control information is created so that the transmission power is reduced by 1 dB. When the bit sequence is “0”, Instantaneous transmission power control information is created so as to increase the transmission power by 1 dB.
[0062]
2) If the bit sequence included in the received transmission power control bits includes many “1”, instantaneous transmission power control information is created so that the transmission power is reduced by 0.5 dB, and “0” is included in the bit sequence. If many are included, instantaneous transmission power control information is created so as to increase the transmission power by 0.5 dB.
[0063]
3) When the bit sequence included in the received transmission power control bits is “11”, instantaneous transmission power control information is created so as to lower the transmission power by 1.5 dB, and when the bit sequence is “10”. Creates instantaneous transmission power control information so as to lower the transmission power by 0.5 dB, and increases the transmission power by 0.5 dB when the bit sequence included in the received transmission power control bits is “00”. Instantaneous transmission power control information is created. If the bit sequence is “01”, instantaneous transmission power control information is created so that the transmission power is increased by 1.5 dB.
[0064]
The interference signal power detection unit 122 and the reception SIR calculation unit 124 measure the reception power of the desired signal from the base station and the interference signal power, and execute a process of calculating the reception SIR.
[0065]
Required SIR determining section 123 determines a required SIR corresponding to a satisfactory reception SIR of the signal from the base station. The required SIR may be stored in a memory or the like in advance.
[0066]
The SIR comparison unit 125 compares the received SIR calculated by the received SIR calculation unit 124 with the required SIR determined by the required SIR determination unit 123.
[0067]
The comparison result of SIR comparing section 123 is sent to control bit determining section 126.
[0068]
Control bit determining section 126 generates a predetermined bit sequence corresponding to the comparison result, and determines a transmission power control bit including the bit sequence.
[0069]
The bit sequence is generated by one of the following methods, for example.
[0070]
1) The magnitude relationship between the received SIR and the required SIR is indicated by one bit. For example, if the received SIR is larger than the required SIR, the bit sequence is set to “1”, and if the received SIR is smaller than the required SIR, the bit sequence is set to “0”.
[0071]
2) The magnitude relationship between the received SIR and the required SIR is indicated by one bit, and the information of the one bit is repeated. For example, when the received SIR is larger than the required SIR, the bit sequence is set to “11111”, and when the received SIR is smaller than the required SIR, the bit sequence is set to “00000”.
[0072]
3) Use Gray code. For example, if the value obtained by subtracting the required SIR from the received SIR is 1 dB or more, the bit sequence is set to “11”. The sequence is "00", and if less than -1 dB, the bit sequence is "01".
[0073]
As another embodiment, it is possible to use an error correction code.
[0074]
The transmission power control bits determined by control bit determination section 126 are supplied to frame generation section 130. Frame generating section 130 inserts this transmission power control bit into an upstream frame sent to base station 200.
[0075]
Next, the mobile station transmitter blocks 130 to 140 will be described. The frame generation unit 130 receives the transmission power control bits, information data, pilot data, and the like, generates an uplink signal frame, and outputs the generated frame to the spreading unit 132.
[0076]
The frame generation unit 130 determines the optimal power amount (E ₀ ), The process of determining the number of transmission power control bits determined by the control bit determination unit 126 is performed.
[0077]
Here, "optimum electric energy (E ₀ ")" Means the amount of control bit power that minimizes the required transmission power of the entire dedicated channel when SIR measurement for transmission power control is performed using only control bits. The number of bits is determined when the power amount of the control bit is E ₀ Allocate the number of bits so that That is, when arranging the control bits, the power is made equal to that of the data bit portion, and the number of bits is increased or decreased to adjust the power amount. ₀ Assign.
[0078]
The optimum power amount determination unit 131 determines the optimum power amount (E ₀ ) May be stored in a memory or the like.
[0079]
Spreading section 132 spreads the input signal using the pseudo noise (PN) code generated by spreading code generating section 134. The signal spread by the spreading section 132 is adjusted by the amplitude adjustment section 135 based on the instantaneous transmission power control information determined by the transmission power determination section 120, and then subjected to quadrature modulation or the like by the modulator 136, and the RF section up. The signal is input to the power amplifier 140 via the converter 138. The power amplifier 140 amplifies the input signal and transmits the output signal.
[0080]
Further, the amplitude adjusting unit 135 determines the optimum power amount (E ₀ ), The power amount of the control bit is E ₀ Assign so that
[0081]
In the present embodiment, the case where “reception quality” and “required quality” are determined using a desired signal reception signal power to interference power ratio (SIR) is described as an example. The “reception quality” and the “required quality” may be determined using a bit error rate (BER: Bit Error Rate), a frame error rate (FER: Frame Error Rate), and the like.
[0082]
FIG. 6 is a block diagram showing an example of a configuration of a CDMA base station according to the present invention.
[0083]
In FIG. 6, blocks denoted by the same reference numerals as those in FIG. 5 have the same functions, and thus description thereof will be omitted.
[0084]
The base station is basically composed of the same blocks as the mobile station. However, in the case of the base station, since it is necessary to receive channels of a plurality of users (mobile stations) at the same time, the despreading unit 108 sends the amplitude adjustment unit 135 to the base station. Up to a plurality. Also, in the mobile station, spreading is performed only by spreading section 132, but in the base station, spreading is performed separately in first spreading for separating channels and second spreading for identifying cells. , A first diffusion unit 202 and a second diffusion unit 204. Also, since the second spreading in the second spreading section 204 is for the purpose of cell division, and it is necessary to perform spreading once for all channels, the adder 206 coupled to the amplitude adjusting section 135 uses the channel for a plurality of users. Is added, and then the second spreading is performed.
[0085]
(Embodiment 1)
FIG. 7 is a diagram illustrating a configuration of a frame according to the first embodiment of the present invention.
[0086]
The frame 700 includes a control bit portion 702 and a data bit portion 704. The frame 700 is, for example, a transmission power control transmission medium transmitted from the transmitting station to the receiving station, that is, a transmission power control transmission signal.
[0087]
In FIG. 7, the vertical axis is Transmission power , And the horizontal axis indicates the number of bits.
[0088]
E in FIG. ₀ Indicates the amount of control bit power that minimizes the required transmission power of the entire dedicated channel when SIR measurement for transmission power control is performed using only control bits, ₁ Indicates the amount of power that satisfies the required quality of the control bit itself.
[0089]
E ₀ And E ₁ Although the absolute value and the magnitude relationship of each vary depending on the transmission speed of the individual channel, etc. ₀ Is E ₁ If the power amount of the control bit is larger than E as shown in FIG. ₀ Assign so that Further, as shown in FIG. 7, when arranging the control bits, the power is made equal to the data bit portion, and the number of bits is adjusted to obtain a desired power amount E. ₀ Assign.
[0090]
FIG. 8 is a flowchart showing a method of creating a frame according to Embodiment 1 of the present invention.
[0091]
First, in step S801, the optimum point E of the power amount of the control bit so as to minimize the required transmission power of the dedicated channel. ₀ To determine.
[0092]
Next, in step S802, the transmission power amount of the control bit becomes E ₀ The number of control bits is determined so that
[0093]
E ₀ Is E ₁ If it is larger than ₀ Is allocated to the control bits, the required transmission power of the dedicated channel can be reduced, and the channel capacity can be increased, while maintaining the quality of the control bits themselves at or above the required quality.
[0094]
Furthermore, E ₀ When allocating the amount of power to the control bits, the power of the control bits and the power of the data bits are made equal, and the number of control bits is adjusted, so that the transmission power can be kept constant over time, And the efficiency of the transmission amplifier can be increased.
[0095]
(Embodiment 2)
FIG. 9 is a diagram showing a configuration of a frame according to Embodiment 2 of the present invention.
[0096]
The frame 900 includes a control bit portion 902 and a data bit portion 904. The frame 900 is, for example, a transmission power control transmission medium transmitted from the transmitting station to the receiving station, that is, a transmission power control transmission signal.
[0097]
In FIG. 9, the vertical axis is Transmission power , And the horizontal axis indicates the number of bits.
[0098]
E in FIG. ₀ , E ₁ Is the amount of power conforming to the first embodiment.
[0099]
As in the first embodiment, E ₀ Is E ₁ If the power amount of the control bit is larger than ₀ Assign so that Further, in the present embodiment, as shown in FIG. 9, when arranging control bits, the power of the control bit portion is offset from the power of the data bit portion to obtain a desired power amount E. ₀ Assign.
[0100]
FIG. 10 is a flowchart showing a method of creating a frame according to Embodiment 2 of the present invention.
[0101]
First, in step S1001, the optimal point E of the power amount of the control bit so as to minimize the required transmission power of the dedicated channel. ₀ To determine.
[0102]
Next, in step S1002, the transmission power amount of the control bit is E ₀ The offset of the control bit is determined so that ₀ Assign.
[0103]
E ₀ Is E ₁ E if it is larger than ₀ By allocating this amount of power to the control bits, the required transmission power of the dedicated channel can be reduced and the channel capacity can be increased, while maintaining the quality of the control bits themselves at or above the required quality.
[0104]
Furthermore, E ₀ By allocating the control bit power to the control bits when allocating the power amount to the control bits, a flexible bit arrangement can be realized by adjusting the power of the control bits to the power of the data bits. Therefore, the power amount of the control bits can be more strictly optimized from the viewpoint of capacity.
[0105]
Next, a transmission power control procedure according to the present invention will be described with reference to FIGS.
[0106]
(Embodiment 3)
FIG. 11 is a flowchart showing a transmission power control procedure according to Embodiment 3 of the present invention.
[0107]
Step S 1302 , The first wireless station measures the reception quality of the signal transmitted by the second wireless station. Here, the “reception quality” means at least one of a desired signal reception signal power to interference power ratio (SIR), reception power, a bit error rate (BER: Bit Error Rate), and a frame error rate (FER: Frame Error Rate). Including one.
[0108]
Next, step S 1304 In, the reception quality is compared with the required quality. Here, “required quality” refers to reception quality that can satisfy a predetermined standard.
[0109]
Next, step S 1306 Generates a bit sequence corresponding to the comparison result. The bit sequence is generated by one of the following methods, for example.
[0110]
1) The magnitude relationship between the reception quality and the required quality is indicated by one bit. For example, when the reception quality is higher than the required quality, the bit sequence is set to “1”, and when the reception quality is lower than the required quality, the bit sequence is set to “0”.
[0111]
2) The magnitude relationship between the reception quality and the required quality is indicated by one bit, and the information of the one bit is repeated. For example, if the reception quality is higher than the required quality, the bit sequence is set to “11111”, and if the reception quality is lower than the required quality, the bit sequence is set to “00000”.
[0112]
3) Use Gray code. For example, if the value obtained by subtracting the required quality from the reception quality is 1 dB or more, the bit sequence is set to “11”; if it is 0 dB or more and less than 1 dB, the bit sequence is set to “10”; The sequence is set to “00”, and if less than −1 dB, the bit sequence is set to “01”.
[0113]
As another embodiment, it is possible to use an error correction code.
[0114]
Next, step S 1308 In, a control bit including the generated bit sequence is generated.
[0115]
Next, step S 1310 , A frame including a control bit is configured.
[0116]
Regarding the frame configuration procedure, the frame is configured by the frame configuration procedure described in the first embodiment (see FIGS. 7 and 8) and / or the frame configuration procedure described in the second embodiment (see FIGS. 9 and 10). Constitute.
[0117]
Next, step S 1312 , The frame is transmitted to the second wireless station.
[0118]
Next, step S 1314 , The second wireless station receives the frame.
[0119]
Next, step S 1316 In, the transmission power is adjusted based on the bit sequence included in the frame. Adjustment of the transmission power is performed, for example, by any of the following methods.
[0120]
1) When the bit sequence included in the received transmission power control bits is “1”, instantaneous transmission power control information is created so that the transmission power is reduced by 1 dB. When the bit sequence is “0”, Instantaneous transmission power control information is created so as to increase the transmission power by 1 dB.
[0121]
2) If the bit sequence included in the received transmission power control bits includes many “1”, instantaneous transmission power control information is created so that the transmission power is reduced by 0.5 dB, and “0” is included in the bit sequence. If many are included, instantaneous transmission power control information is created so as to increase the transmission power by 0.5 dB.
[0122]
3) When the bit sequence included in the received transmission power control bits is “11”, instantaneous transmission power control information is created so as to lower the transmission power by 1.5 dB, and when the bit sequence is “10”. Creates instantaneous transmission power control information so as to lower the transmission power by 0.5 dB, and increases the transmission power by 0.5 dB when the bit sequence included in the received transmission power control bits is “00”. Instantaneous transmission power control information is created. If the bit sequence is “01”, instantaneous transmission power control information is created so that the transmission power is increased by 1.5 dB.
[0123]
Through the above procedure, the transmission power on the line from the second wireless station to the first wireless station is controlled.
[0124]
(Embodiment 4)
FIG. 12 is a flowchart showing a transmission power control procedure according to Embodiment 4 of the present invention.
[0125]
First, step S 1402 , The first wireless station configures a frame including control bits.
[0126]
Regarding the frame configuration procedure, the frame is configured by the frame configuration procedure described in the first embodiment (see FIGS. 7 and 8) and / or the frame configuration procedure described in the second embodiment (see FIGS. 9 and 10). Constitute.
[0127]
Next, step S 1404 , The frame is transmitted to the second wireless station.
[0128]
Next, step S 1406 , The second wireless station receives the frame.
[0129]
Next, step S 1408 Measuring the reception quality of the signal transmitted by the first wireless station. Here, the measurement of the reception quality may be measured using at least a part of the control bits transmitted by the first wireless station (that is, a part or all of the control bits), or at least a part of the control bits. And at least some of the data bits (ie, some or all of the control bits and data bits).
[0130]
Next, step S 1410 In, the reception quality is compared with the required quality.
[0131]
Next, step S 1412 Generates a bit sequence corresponding to the comparison result.
[0132]
Next, step S 1414 , The bit sequence is transmitted to the first wireless station.
[0133]
Next, in step S1416, the first wireless station receives the bit sequence transmitted by the second wireless station.
[0134]
Next, step S 1418 In, the transmission power is adjusted based on the bit sequence.
[0135]
Through the above procedure, the transmission power on the line from the first wireless station to the second wireless station is controlled.
[0136]
【The invention's effect】
As explained above, the present invention ₀ By allocating the power amount of the control bits to the control bits and optimizing the distribution of the control bits and the data bits, the required transmission power of the individual channel can be reduced while maintaining the quality of the control bits itself at or above the required quality. Can be increased.
[0137]
Also, E ₀ When allocating the amount of power to the control bits, the power of the control bits and the power of the data bits are made equal, and the number of control bits is adjusted, so that the transmission power can be kept constant over time, And the efficiency of the transmission amplifier can be increased.
[0138]
Furthermore, E ₀ By allocating the control bit power to the control bits when allocating the power amount to the control bits, a flexible bit arrangement can be realized by adjusting the power of the control bits to the power of the data bits. Therefore, the power amount of the control bits can be more strictly optimized from the viewpoint of capacity.
[Brief description of the drawings]
FIG. 1 is a diagram showing interference from another mobile station on an uplink in a conventional example.
FIG. 2 is a diagram illustrating an example of an individual channel configuration of a CDMA mobile communication system according to the related art.
FIG. 3 is a graph showing the relationship between the amount of control bit power per slot and the bit error rate in a conventional CDMA mobile communication system.
FIG. 4 is a graph showing the relationship between the amount of control bit power per slot and the required transmission power of the entire dedicated channel when SIR measurement of transmission power control is performed using only control bits according to the present invention.
FIG. 5 is a block diagram showing an example of a configuration of a CDMA mobile station according to the present invention.
FIG. 6 is a block diagram showing an example of a configuration of a CDMA base station according to the present invention.
FIG. 7 is a diagram showing a configuration of a frame according to the first embodiment of the present invention.
FIG. 8 is a flowchart showing a frame creation method according to the first embodiment of the present invention.
FIG. 9 is a diagram showing a configuration of a frame according to the second embodiment of the present invention.
FIG. 10 is a flowchart showing a method for creating a frame according to the second embodiment of the present invention.
FIG. 11 is a flowchart showing a transmission power control procedure according to Embodiment 3 of the present invention.
FIG. 12 is a flowchart showing a transmission power control procedure according to Embodiment 4 of the present invention.
[Explanation of symbols]
100 mobile stations
102 RF unit and down converter
104 AGC amplifier
106 Quadrature detector
108 Despreading unit
110 demodulator / rake combiner
114 Timing Generator
116 Desired signal power detector
120 transmission power determination unit
122 Interference signal power detection unit
123 Required SIR determination unit
124 reception SIR calculator
125 SIR determination unit
126 control bit determination unit
130 Frame generation unit
131 Optimal electric energy determination unit
132 Diffusion unit
134 Spreading code generator
136 modulator
138 RF Unit / Up Converter
140 power amplifier
200 base stations
202 First diffusion unit
204 Second diffusion unit
206 adder

Claims (27)

A frame configuration method in a CDMA mobile communication system,
Setting an optimal amount of power to be allocated to the control bit portion ;
Making the transmission power of the control bits included in the control bit portion equal to the transmission power of the data bits included in the data bit portion ;
By adjusting the number of bits of the control bit portion, the amount of transmit power allocated to the control bit part, a frame configuration method characterized by comprising the step of said optimum power. A frame configuration method in a CDMA mobile communication system,
Setting an optimal amount of power to be allocated to the control bit portion ;
Adjusting the transmission power of the control bits included in the control bit portion independently of the transmission power of the data bits included in the data bit portion, thereby setting the transmission power amount allocated to the control bit portion to the optimum power amount. And a frame configuration method. 3. The frame configuration method according to claim 1, wherein the optimal power amount of the control bit portion is a power amount that minimizes required transmission power of the entire dedicated channel. 4. A frame configuration device in a CDMA mobile communication system,
Means for setting an optimal amount of power to be allocated to the control bit portion ;
Means for making the transmission power of the control bits included in the control bit portion equal to the transmission power of the data bits included in the data bit portion ,
The number of bits by adjusting the control bit portion, the amount of transmit power allocated to the control bit part, the optimum amount of power and frame configuration apparatus characterized by comprising a means for. A frame configuration device in a CDMA mobile communication system,
Means for setting an optimal amount of power to be allocated to the control bit portion ;
Means for adjusting the transmission power amount of the control bits included in the control bit portion independently of the transmission power of the data bits included in the data bit portion so that the transmission power amount allocated to the control bit portion is the optimum power amount. And a frame configuration device. 6. The frame configuration apparatus according to claim 4, wherein the optimum power amount of the control bit portion is a power amount that minimizes required transmission power of the entire dedicated channel. A frame configuration in a CDMA mobile communication system , wherein a data bit portion including a data bit having a transmission power equal to a transmission power of a control bit included in a control bit portion, and a bit number adjusted to be an optimal power amount. frame structure, characterized in that a said control bit part was. A frame configuration in a CDMA mobile communication system, wherein the transmission power amount is adjusted to an optimum power by adjusting the transmission power of control bits included in a control bit portion independently of the transmission power of data bits included in a data bit portion. A frame structure comprising a control bit portion in a reduced amount. In the frame structure according to claim 7 or claim 8, wherein the optimal power amount of the control bit portion, a frame structure, characterized in that the amount of power the minimum required transmit power of the entire individual channels. In the frame structure according to any one of claims 7 to 9, the frame structure and the control bit part is characterized in that it comprises a bit sequence corresponding to a result of comparison between the reception quality and the required quality. A frame structure according to any one of claims 7 to 10, a frame structure in which the frame structure is characterized in that it is transmitted as a transmission signal. A transmission power control method,
In the first radio station,
Measuring the reception quality of the signal transmitted by the second wireless station;
Comparing the reception quality measured by the measuring step with required quality,
Generating a bit sequence corresponding to the comparison result of the comparing step;
Generating a control bit portion including the bit sequence generated by the step of generating the bit sequence;
Setting an optimal amount of power to be allocated to the control bit portion ;
Making the transmission power of the control bits included in the control bit portion equal to the transmission power of the data bits included in the data bit portion ;
A step by adjusting the number of bits of the control bit portion of the amount of transmit power allocated to the control bit portion, and the optimum amount of power,
Configuring a frame including the control bit portion that is the optimal power amount by the step of the optimal power amount,
Transmitting the frame to the second wireless station, and at the second wireless station,
Receiving the frame transmitted by the transmitting step;
Adjusting the transmission power based on the bit sequence included in the frame received in the receiving step. A transmission power control method,
In the first radio station,
Measuring the reception quality of the signal transmitted by the second wireless station;
Comparing the reception quality measured by the measuring step with required quality,
Generating a bit sequence corresponding to the comparison result of the comparing step;
Generating a control bit portion including the bit sequence generated by the step of generating the bit sequence;
Setting an optimal amount of power to be allocated to the control bit portion ;
Adjusting the transmission power of the control bits included in the control bit portion independently of the transmission power of the data bits included in the data bit portion, thereby setting the transmission power amount allocated to the control bit portion to the optimum power amount. And constructing a frame including the control bit portion that was the optimal power by the step of the optimal power,
Transmitting the frame to the second wireless station, and at the second wireless station,
Receiving the frame transmitted by the transmitting step;
Adjusting the transmission power based on the bit sequence included in the frame received in the receiving step. 14. The transmission power control method according to claim 12, wherein the optimum power amount of the control bit portion is a power amount that minimizes required transmission power of the entire dedicated channel. Method. A radio station,
Means for measuring the reception quality of the received signal;
Means for comparing the reception quality measured by the measuring means with the required quality,
Means for generating a bit sequence corresponding to the comparison result of the comparing means,
Means for generating a control bit portion including the bit sequence generated by the means for generating the bit sequence,
Means for setting an optimal amount of power to be allocated to the control bit portion ,
Means for making the transmission power of the control bits included in the control bit portion equal to the transmission power of the data bits included in the data bit portion ,
By adjusting the number of bits of the control bit portion, the amount of transmit power allocated to the control bit part, and means to said optimum power amount,
Means for configuring a frame including the control bit portion which has been set to the optimum power amount by means for the optimum power amount,
Means for transmitting the frame. A radio station,
Means for measuring the reception quality of the received signal;
Means for comparing the reception quality measured by the measuring means with the required quality,
Means for generating a bit sequence corresponding to the comparison result of the comparing means,
Means for generating a control bit portion including the bit sequence generated by the means for generating the bit sequence,
Means for setting an optimal amount of power to be allocated to the control bit portion ,
Means for adjusting the transmission power amount of the control bits included in the control bit portion independently of the transmission power of the data bits included in the data bit portion so that the transmission power amount allocated to the control bit portion is the optimum power amount. Means for configuring a frame including the control bit portion which has been set to the optimum power amount by the means for setting the optimum power amount;
Means for transmitting the frame. 17. The radio station according to claim 15, wherein the optimum power amount of the control bit portion is a power amount that minimizes required transmission power of the entire dedicated channel. A radio station,
Means for receiving the frame transmitted by the means for transmitting the frame, wherein the wireless station according to any one of claims 15 to 17,
Means for adjusting transmission power based on the bit sequence included in the frame received by the means for receiving the frame. A transmission power control method,
Setting an optimum amount of power to be allocated to the control bit portion in the first wireless station;
Making the transmission power of the control bits included in the control bit portion equal to the transmission power of the data bits included in the data bit portion ;
A step by adjusting the number of bits of the control bit portion, the amount of transmit power allocated to the control bit portion, and the optimum amount of power,
Configuring a frame including the control bit portion that is the optimal power amount by the step of the optimal power amount,
Transmitting the frame to a second wireless station;
Measuring, at the second wireless station, reception quality of a signal transmitted by the first wireless station;
Comparing the reception quality measured by the measuring step with required quality,
Generating a bit sequence corresponding to the comparison result of the comparing step;
Transmitting the bit sequence generated by the step of generating the bit sequence to the first wireless station;
At the first wireless station, receiving the bit sequence transmitted by the second wireless station;
Adjusting the transmission power based on the bit sequence received in the receiving step. A transmission power control method,
Setting an optimum amount of power to be allocated to the control bit portion in the first wireless station;
Adjusting the transmission power of the control bits included in the control bit portion independently of the transmission power of the data bits included in the data bit portion, thereby setting the transmission power amount allocated to the control bit portion to the optimum power amount. And constructing a frame including the control bit portion that was the optimal power by the step of the optimal power,
Transmitting the frame to a second wireless station;
Measuring, at the second wireless station, reception quality of a signal transmitted by the first wireless station;
Comparing the reception quality measured by the measuring step with required quality,
Generating a bit sequence corresponding to the comparison result of the comparing step;
Transmitting the bit sequence generated by the step of generating the bit sequence to the first wireless station;
At the first wireless station, receiving the bit sequence transmitted by the second wireless station;
Adjusting the transmission power based on the bit sequence received in the receiving step. In the transmission power control method according to claim 19 or 20,
The step of measuring the reception quality includes:
A transmission power control method, wherein the measurement is performed using at least a part of the control bit portion transmitted by the first wireless station. In the transmission power control method according to claim 19 or 20,
The step of measuring the reception quality includes:
A transmission power control method, wherein the measurement is performed using at least a part of the control bit portion transmitted by the first wireless station and at least a part of a data bit portion transmitted by the first wireless station. 23. The transmission power control method according to claim 19, wherein the optimum power amount of the control bit portion is a power amount that minimizes required transmission power of the entire dedicated channel. Transmission power control method. In radio stations,
A frame configuration device according to any one of claims 4 to 6,
Means for transmitting a frame configured by the frame configuration device. In radio stations,
Means for receiving the frame transmitted by the means for transmitting the frame by the wireless station according to claim 24,
Means for measuring the reception quality of the frame received by the means for receiving the frame,
Means for comparing the reception quality measured by the measuring means with the required quality,
Means for generating a bit sequence corresponding to the comparison result of the comparing means,
Means for transmitting the bit sequence generated by the means for generating the bit sequence. The radio station according to claim 25,
The means for measuring the reception quality,
The wireless station performs measurement using at least a part of the control bit portion transmitted by the first wireless station. The radio station according to claim 25,
The means for measuring the reception quality,
A radio station, wherein measurement is performed using at least a part of the control bit portion transmitted by the first radio station and at least a part of a data bit portion transmitted by the first radio station.

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