JP2008278523A - Spectrum spread communication system, and transmitter and receiver constituting the system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spectrum spread communication system which transmits and receives a spectrum spread signal generated by subjecting a signal of a slot at least composed of transmission data and a pilot signal to spreading processing, and a transmitter and a receiver constituting the system, whereby a spread code phase is precisely acquired by the receiver at a high speed. <P>SOLUTION: The spectrum spread communication system which transmits and receives the spectrum spread signal generated by subjecting the signal of the slot at least composed of the transmission data and pilot signal to the spreading processing performs transmission power control such that the level of the pilot signal whose phase is detected based upon a transmission power control signal received from a transmitter of a communication partner is made higher than the level of the transmission data. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a spread spectrum communication system and a transmitter and a receiver constituting the system, and in particular, among the spread spectrum signals transmitted by the transmitter, a transmission power is transmitted for a signal portion used by the receiver to acquire a spread code phase. The present invention relates to a spread spectrum communication system in which the accuracy of a spread code phase acquired in a receiver is increased, and a transmitter and a receiver constituting the system.

  A conventional spread spectrum communication system arrives at a delay with respect to the direct wave due to the influence of the direct wave and the reflection of the building, etc., in order to improve the error rate characteristic of the received wave while suppressing the transmission power of the communication partner. So-called RAKE reception is performed to synthesize delayed waves.

  A conventional spread spectrum communication system will be described with reference to FIGS. 4A and 4B represent a conventional spread spectrum communication system. In the figure, 1 is a mobile station, 2 is an antenna, 3 is a high frequency amplifier, 4 is a frequency converter that performs frequency conversion from a radio frequency to an intermediate frequency, 5 is a demodulator, 6 is an A / D converter, and 7 is an input signal. RAKE receivers that perform despreading at different timings to extract direct waves and delayed waves and align the timings, 8 is a correlation unit that correlates input signals, and 9 is a spreading code that gives a spreading code to the correlation unit A generation unit 10 is a phase control unit that controls the phase of the spread code generated by the spread code generation unit 9, and 11 is a unit that controls the phase control unit 10, creates a delay profile, and provides phase information to the RAKE reception unit 7. Control unit, 12 is a searcher, 13 is a coder / decoder, 14 is an A / D converter, 15 is a microphone, 16 is a D / A converter, 17 is a speaker, and 18 is timing control. Timing control unit for performing, 19 is a framing unit for framing transmission data and the like, 20 is a spreading unit for generating a spread spectrum signal, 21 is a D / A converter, 22 is a modulator for modulating, and 23 is from an intermediate frequency Frequency converter for frequency conversion to radio frequency, 24 is a variable gain amplifier capable of controlling the amplification factor, 25 is a transmission power control unit for controlling the amplification factor of the variable gain amplifier, 26 is a base station, and 27 is the SIR of the received signal. (Signal to Interference Ratio) SIR estimation unit 28, SIR determination unit 28 for instructing generation of transmission power control signal, 29 framing unit for framing transmission data, etc. 30 is input Each of the signals to be combined is weighted in proportion to its reliability and then combined (maximum ratio combining).

  First, the spread spectrum signal transmitted from the antenna 2 of the mobile station 1 is received by the antenna 2 of the base station 26, the high frequency component of the received signal is amplified by the high frequency amplifier 3, and the frequency converter 4 intermediates the radio frequency. Down-converted to a frequency, demodulated by the demodulator 5, and then converted into a digital signal by an A / D converter. One of the received signals converted into the digital signal is input to the searcher 12 and the other is input to the RAKE receiving unit 7.

  Now, the signal input to the searcher 12 is correlated with the spreading code created by the spreading code generator 9 by the correlator 8. The spread code is controlled by the phase control unit 10 and is gradually shifted in phase (for example, shifted by about 1/8 of one chip of the spread code). The correlation value obtained as the output is the sum of the squares of the signal input to the searcher 12 and the spreading code. When the phase is correlated, the correlation value must be large. The value will be small. Thereby, the control part 11 acquires the data of the correlation value with respect to the change of a phase. FIG. 5 represents a change in phase on the horizontal axis and a correlation value on the vertical axis, which is called a delay profile. In the figure, B, C, etc. having a large correlation value are considered to be A delayed waves, and the others are considered to be thermal noise, and interference caused by spread spectrum signals emitted from other mobile stations. For example, the control unit 11 provides the RAKE receiving unit 7 with phase information of the top three (A, B, and C in the figure) having a high correlation value. The RAKE receiver 7 performs despreading on each of the direct wave A and the delayed waves B and C using the phase information (spreading code phase) of the direct wave and the delayed wave. Then, delay adjustment is performed according to each delay amount, the timing is adjusted, weighting in proportion to the reliability is performed by the combining unit 30, and then combining (maximum ratio combining) is performed.

  However, the following problems cannot be solved only by performing RAKE reception at the receiver. In general, as the mobile station moves away from the base station, the received electric field strength of signals received at the base station tends to decrease. Therefore, in a spread spectrum communication system aiming at effective use of frequency by distinguishing from signals from other mobile stations by the difference of spreading codes, the base station side is more effective for mobile stations whose received electric field strength has decreased. Therefore, the degree of interference of the spread spectrum signal transmitted from the mobile station existing in the network becomes strong (SIR deteriorates), and noise components cannot be sufficiently removed.

  Such a problem is called a perspective problem. Therefore, transmission power control is performed to solve this perspective problem. That is, regardless of the signal sent from any mobile station, the base station controls the transmission power of the mobile station so that the SIR is all equal, and the mobile station that is located far away from the base station and the mobile that exists nearby Control is performed to eliminate the extreme difference in SIR between stations.

  This control will be described. One of the signals that the RAKE receiving unit 7 in the base station 26 performs the maximum ratio combining based on the phase information from the control unit 11 is transmitted to the base station control station, and the other is estimated by the SIR estimation unit 27 in the SIR estimation. Is done. Then, the SIR determination unit 28 compares the estimated SIR value with a threshold value. When the estimated value falls below the threshold value, the SIR determination unit 28 generates a control signal that causes the framing unit 29 to increase the transmission power of the mobile station. If it exceeds the threshold value, a transmission power control signal generation command signal is transmitted to the framing unit 29 to instruct to generate a control signal for decreasing the transmission power.

  Here, the configuration of the framing unit 29 will be described with reference to FIG. FIG. 6 shows the configuration of the framing unit 29. In the figure, 901 is a buffer for buffering transmission data, 902 is a pilot signal creation unit for creating a pilot signal, 903 is a control signal creation unit for creating a control signal, and 904 is transmission power control for creating a transmission power control signal. A signal creation unit 905 represents a selector for selectively sending an input signal to the spreading unit.

  Transmission data such as an encoded audio signal is input to the buffer 901, and the data is temporarily stored. The read audio data and the like are sent to the diffusion unit 20 via the selector at the timing given from the timing control unit 18. Further, the pilot signal creation unit 902, the control signal creation unit 903, and the transmission power control signal creation unit 904 also send the pilot signal, control signal, and transmission power control signal (2 bits) via the selector 905 at the timing given from the timing control unit 18. It is sent out to the diffusion unit 20. The signal sent to the spreading unit 20 by the timing control unit 18 is controlled in the order of a pilot signal, a transmission power control signal, transmission data, and a control signal (hereinafter, data constituted by one set is defined as one slot. Called).

  However, the transmission power control signal creation unit 904 receives the transmission power control signal creation command signal from the SIR determination unit 28, and increases the transmission power of the mobile station (for example, +1.0 dB). When it receives, it outputs “11”, and when it receives a control signal creation command to lower (−1.0 dB), it outputs “00”. When the transmission power control signal creation command signal is not transmitted from the SIR determination unit 28, for example, the signals “11” and “00” are alternately transmitted to maintain the average transmission power. Is going.

  The signal subjected to the timing control is transmitted to the spreading unit 20, subjected to code spreading processing, and converted into an analog signal by the D / A converter 21. The analog signal is modulated by a modulator 22, converted from an intermediate frequency to a radio frequency by a frequency converter 23, amplified by a variable gain amplifier 24, and transmitted from the antenna 2 to the mobile station 1. .

  On the other hand, the mobile station 1 receives the spread spectrum signal including the transmission power control signal from the base station 26 via the antenna 2, the high frequency amplifier 3, the frequency converter 4, the demodulator 5, and the A / D converter 6. The RAKE receiving unit 7 performs RAKE reception of the received signal based on the phase information detected by the searcher 12 (configured by the correlation unit 8, the spread code generation unit 9, the phase control unit 10, and the control unit 11). . Then, the transmission power control signal included in the signal after RAKE reception is sent to the transmission power control unit 25.

  The other signals after receiving the RAKE are decoded by the coder / decoder 13 and output as sound from the speaker 17 via the D / A converter 16. The voice input from the microphone 15 is encoded by the A / D converter 14 and the coder / decoder 13 and input to the framing unit 19 as transmission data. The configuration of the framing unit 19 will be described with reference to FIG. FIG. 7 shows an example of the configuration of the framing unit 19.

  In the figure, the same reference numerals as those in FIG. 6 denote the same members. Transmission data such as audio data is input to the buffer 901, and the data is temporarily stored. The audio data read out at the timing given from the timing control unit 18 is sent to the diffusion unit 20 via the selector. Further, the pilot signal creation unit 902, the control signal creation unit 903, and the transmission power control signal creation unit 904 also send the pilot signal, control signal, and transmission power control signal to the spreading unit 20 via the selector 905 at the timing given by the timing control unit 18. To send. The signal sent to the spreading unit 20 by the timing control unit 18 creates a pilot signal, a transmission power control signal (“11”, “00”, etc.). Ignored), transmission data, and control signal in this order.

  The signal subjected to the timing control is code-spread by the spreader 20, modulated by the modulator 22, frequency-converted by the frequency converter 23, and then input to the variable gain amplifier 24. Here, the transmission power control unit 25 that has received the transmission power control signal controls the gain of the variable gain amplification unit 24 at the leading timing of one slot acquired from the timing control unit 18. That is, if the transmission power control signal is “11”, the amplification factor is increased, the transmission power is maintained until the next “00” signal is received, and if “00”, the amplification factor is decreased. The transmission power is maintained until the signal “11” is received.

Therefore, the signal transmitted from the antenna 2 of the mobile station 1 is subjected to transmission power control for SIR equalization. When the base station 26 receives the signal, the SIR after receiving the RAKE is within the threshold. As a result, the SIR becomes uniform with other mobile stations that receive the same control. The above is the transmission power control (SIR equalization control) for solving the perspective problem performed in the conventional spread spectrum communication system.
Japanese Patent Application Laid-Open No. 07-221700 JP 09-046270 A JP-A-10-190497

  As described above, the conventional spread spectrum communication system measures the correlation value by the correlation unit 8 in the searcher 12 and performs RAKE reception based on the phase information obtained from the result. However, in order to effectively perform RAKE reception, it is necessary to detect this phase information by integrating the correlation values detected at different timings a plurality of times. This is because the difference between the interference wave and the delayed wave does not appear as a difference in the correlation value by only one correlation value measurement. Therefore, the phase information of the delayed wave cannot be detected accurately, and errors due to the synthesis of the delayed wave. This is because the rate characteristic cannot be improved.

  However, although the RAKE reception is performed effectively, the number of correlation value integration processes cannot be increased without limit. This is because the increase in the number of integration processes causes a harmful effect of lowering the followability of the phase information with respect to the phase change of the delayed wave accompanying the movement of the mobile station. On the other hand, in order to avoid this, a method of improving the phase information detection speed by limiting the measurement target of the correlation value to one mobile station and continuously performing the measurement of the correlation value performed at different timings. If it is adopted, the process of obtaining the correlation value while shifting 1/8 of one chip of the spreading code will be performed continuously, and the problem that the process of the searcher 12 cannot catch up. Will be monopolized continuously, resulting in a new problem of hindering the delay profile creation of other mobile stations.

  Therefore, in practice, the number of integration processes is limited to a range that is not sufficient to obtain highly accurate phase information, and delay waves are synthesized based on the phase information with reduced accuracy. Therefore, the deterioration of the error rate characteristic is allowed. In addition, the transmission power control of the mobile station for SIR equalization, which is performed as a solution to the near-far problem, is also performed based on the phase information with reduced accuracy as described above, and the SIR estimation result of the signal after RAKE reception Since the accuracy of the phase information used for RAKE reception is low even though the transmission power is sufficient, it is considered that the SIR is apparently deteriorated, and transmission power control that is not necessary originally is performed. As a result, interference with other mobile stations has been strengthened.

  Accordingly, an object of the present invention is to suppress the number of integration processes in a searcher and to obtain a spread code phase with high speed and accuracy. Another object of the present invention is to solve a true perspective problem by using the spread spectrum communication system.

  In the present invention, in a spread spectrum communication system including a transmitter and a receiver that perform communication by transmitting and receiving a spread spectrum signal obtained by performing spread processing on a signal of a slot composed of at least transmission data and a pilot signal. Has an acquisition means for acquiring a spread code phase of a spread spectrum signal from the transmitter, and the transmitter has a spread means of the spread spectrum signal to be transmitted to the receiver. It has a transmission power control means for performing transmission power control for making the level of the spread spectrum signal of the part used for acquiring the code phase higher than the level of the spread spectrum signal of the part not used for acquiring the spreading code phase. A spread spectrum communication system is used.

  In the present invention, it is possible to use a spread spectrum communication system in which the part of the spread spectrum signal used by the receiver acquisition means for acquiring the spread code phase is a pilot signal.

  Also, in the present invention, a transmitter that transmits a spread spectrum signal obtained by performing spread processing on a signal of a slot that is configured with at least transmission data and a pilot signal transmits a predetermined signal among the transmitted spread spectrum signals. A transmitter characterized by having transmission power control means for performing transmission power control for increasing the transmission power at the time of transmission from a level other than a predetermined signal is used.

  In the present invention, a transmitter in which a predetermined signal is a pilot signal among the spread spectrum signals to be transmitted can be used.

  Furthermore, in the present invention, in a receiver that receives a spread spectrum signal obtained by performing spread processing on a signal in a slot composed of at least transmission data and a pilot signal, the transmission power of the received spread spectrum signal is increased. A receiver characterized by having acquisition means for acquiring spread code phase information of the received spread spectrum signal by using the signal of the received portion is used.

  In the present invention, it is possible to use a receiver in which the portion of the received spread spectrum signal whose transmission power is increased is a pilot signal.

  According to the present invention, the transmitter transmits a spread spectrum signal with a signal level increased with respect to a signal that the receiver does not use for obtaining the spreading code phase, so that the direct wave, The difference between the delayed wave or the like and the interference wave becomes significant, and the acquisition of the spread code phase in the receiver becomes easy. Therefore, it is possible to acquire the spread code phase at high speed and with high accuracy without taking special measures such as increasing the number of integration processes, and the followability to the change of the spread code phase accompanying the movement of the transmitter is enhanced. In particular, when RAKE reception is performed, RAKE reception can be effectively performed by combining the direct wave and the delayed wave using the high-speed and high-accuracy spreading code phase, and errors after RAKE reception can be achieved. Rate characteristics can also be improved. Note that the control for increasing the transmission power in the present invention is performed (preferentially) for the signal portion used for obtaining the spread code phase in the receiver, and is given to other transmitters than the control for uniformly increasing the transmission power. Interference can be kept low.

  Examples of the present invention will be described below. In the present invention, the correlation value in the searcher in the base station is obtained by controlling the transmission power of the mobile station so that the signal level that is the target of measurement of the correlation value in the base station is higher than the level of the non-measurement target signal. It is possible to improve the error rate characteristics after RAKE reception while suppressing the number of integration processes.

  The operation of the spread spectrum communication system of the present invention will be described with reference to FIGS. 1A and 1B show an example of the configuration of a spread spectrum communication system according to the present invention. In the figure, the same reference numerals as those in FIGS. 4-a and -b denote the same members.

  The base station 26 is used as a receiver, the mobile station 1 is used as a transmitter, the searcher 12 is used as an acquisition unit, and the timing control unit 18 and the transmission power control unit 25 are used as transmission power control units. Further, the framing unit 19 including the transmission power control signal generation unit 904, the spreading unit 20, the D / A converter, the modulator 22, the frequency converter 23, the variable gain amplifier 24, and the antenna 2 are used as the request unit.

  The spread spectrum signal transmitted from the antenna 2 of the mobile station 1 is received by the antenna 2 of the base station 26, the high frequency component is amplified by the high frequency amplifier 3, and is down converted from the radio frequency to the intermediate frequency by the frequency converter 4. Demodulated by the demodulator 5. The demodulated signal is converted to a digital signal by the A / D converter 6 and input to the searcher 12. The searcher 12 detects the phase information and sends the phase information to the RAKE receiving unit 7 by the same processing as in the above-described conventional technology.

  The RAKE receiving unit 7 performs despreading for each of the direct wave and the delayed wave based on the phase information. Then, after adjusting the delay according to each delay amount and adjusting the timing, the combining unit 30 performs combining (maximum ratio combining) after weighting in proportion to the reliability. One of the signals that the RAKE receiving unit 7 in the base station 26 performs the maximum ratio combining based on the phase information from the control unit 11 is transmitted to the base station control station, and the other is estimated by the SIR estimation unit 27 in the SIR estimation. Is done.

  Then, the SIR determination unit 28 compares the estimated SIR value with a threshold value. When the estimated value falls below the threshold value, the SIR determination unit 28 causes the framing unit 29 to increase the transmission power of the mobile station 1 (hereinafter referred to as “U”). When the signal exceeds the threshold, the U and D signal creation command signals are sent to the framing unit 29 so as to create a control signal (hereinafter referred to as D signal) that lowers the transmission power. When sending the U signal generation command signal to the framing unit 29, the correlation value is always measured for a predetermined portion of a signal (eg, a PILOT signal) previously determined with the mobile station in the received signal. A signal (hereinafter, this signal is referred to as a special measurement signal) is transmitted to the control unit 11.

  Here, the configuration of the framing unit 29 will be described with reference to FIG. FIG. 2 shows an example of the configuration of the framing unit 29. In the figure, the same reference numerals as those in FIG. 6 denote the same members. Transmission data such as voice data, a pilot signal created by the pilot signal creation unit 902, a control signal created by the control signal creation unit 903, and a transmission power control signal created by the transmission power control signal creation unit 904 are: The signal is sent to the diffusion unit 20 via the selector 905 at the timing given from the timing control unit 18. However, the transmission power control signal generation unit 904 receives the U and D signal generation command signal from the SIR determination unit 28, and receives the command to transmit the U signal (for example, “11”) and the D signal (for example, “ 00 ").

  The signal including the transmission power control signal code-spreaded by the spreading unit 20 is converted into an analog signal by the D / A converter 21 and modulated by the modulator 22. The modulated signal is converted to a radio frequency by the frequency converter 23, amplified by the variable gain amplifier 24, and transmitted from the antenna 2. Similarly, the mobile station 1 receives the signal transmitted from the base station 26 via the antenna 2, the high frequency amplifier 3, the frequency converter 4, the demodulator 5, and the A / D converter 6, and receives the received signal from the RAKE. To the unit 7 and the searcher 12 (configured by the correlation unit 8, the spread code generation unit 9, the phase control unit 10, and the control unit 11).

  As described above, the searcher 12 acquires the phase information of the direct wave and the delayed wave, and gives the phase information to the RAKE receiving unit 7. The RAKE receiving unit 7 performs despreading for each of the direct wave and the delayed wave based on the phase information. Then, after adjusting the delay according to the respective delay amounts to adjust the timing, weighting in proportion to the reliability is performed, and then synthesis (maximum ratio synthesis) is performed.

  Among the combined signals, U and D signals that are transmission power control signals are transmitted to the transmission power control unit 25. Of the other signals, the audio signal is decoded by the coder / decoder 13, converted into an analog signal by the D / A converter 16, and then output from the speaker 17 as audio. Also, the sound input from the microphone 15 is converted into a digital signal by the A / D changer 14 and input to the coder / decoder 13, which encodes the sound signal and gives it to the framing unit 19.

  Here, the configuration of the framing unit 19 will be described with reference to FIG. FIG. 3 shows an example of the configuration of the framing unit 19. In the figure, the same reference numerals as those in FIG. 2 denote the same members. Transmission data such as audio data is input to the buffer 901, and the data is temporarily stored. Then, at the timing given from the timing control unit 18, the divided audio data and the like are sent out to the diffusion unit 20 via the selector. In addition, the pilot signal creation unit 902, the control signal creation unit 903, the transmission power control signal creation unit 904 (“11”, “00”, etc.) are created, but in any case, the base station 26 normally ignores this signal. The pilot signal, the control signal, and the transmission power control signal are sent to the spreading unit 20 via the selector 905 at the timing given from the timing control unit 18. The signal sent to the spreading unit 20 is controlled by the timing control unit 18 in the order of a pilot signal, a transmission power control signal, transmission data, and a control signal.

  The signal subjected to the timing control is code-spread by the spreader 20, converted to an analog signal by the D / A converter 21, modulated by the modulator 22, and then converted to a radio frequency by the frequency converter 23. Converted. The signal converted to the radio frequency is input to the variable gain amplifier 24 and amplified. However, the amplification factor is controlled by the transmission power control unit 25. That is, the transmission power control signal (U, D signal) among the spread spectrum signals transmitted from the base station 26 is input to the transmission power control unit 25, and the transmission power control signal is a D signal (“00”). The gain of the variable gain amplifying unit 24 is decreased by a predetermined value (for example, −0.1 dB) at the leading timing of one slot acquired from the timing control unit 18, and then the U and D signals are received. Keep the gain down. However, when the U signal (“11”) is received, the amplification factor of the variable gain amplifier 24 is increased (+0.1 dB) at the leading timing of one slot acquired from the timing control unit 18, but is previously transmitted to the base station. Only when a predetermined signal (for example, PILOT signal) is transmitted, the amplification factor is further increased (for example, +5.0 dB).

  The gain control in the mobile station 1 can always be performed without a request from the base station. However, as in this embodiment, when the base station is instructed to increase the transmission power, the control is performed for a certain period of time. By performing only within, it is possible to minimize the degree of interference with other mobile stations. Therefore, the signal transmitted from the antenna 2 of the mobile station 1 is not only subjected to transmission power control for SIR equalization, but the signal portion used for the correlation value measurement by the correlation unit 8 of the base station 26 is as follows. As a result, the transmission power can be temporarily increased compared to a signal that is not to be measured.

  Now, the signal transmitted from the antenna 2 of the mobile station 1 is received by the base station 26, and the received signal is input to the RAKE receiving unit 7 and the searcher 12. Then, the control unit 11 that has received the special measurement signal from the SIR determination unit 28 performs measurement of the correlation value of the signal (for example, the PILOT signal) of the predetermined part in the reception signal for a predetermined time. For example, at the timing of receiving the PILOT signal), the spreading code generator 9 outputs the spreading code, and the correlator 8 measures the correlation value. However, since this measurement is performed for signals with increased transmission power, noise and the difference between interference from other mobile stations and the delayed wave will appear more prominently as the correlation value. Therefore, it is possible to detect phase information with high accuracy even if the number of integration processing times is the same as that of the prior art or if necessary, the number of integration processings is further sufficiently suppressed.

  The RAKE receiving unit 7 can effectively perform RAKE reception using this highly accurate phase information, and naturally the error rate characteristic of the signal after the RAKE reception is improved. Further, the SIR estimation unit 27 can perform SIR estimation using a signal obtained by effectively synthesizing delayed waves, and can perform appropriate transmission power control of the mobile station 1 for uniformizing SIR. Therefore, it is possible to suppress the influence on other mobile stations due to unnecessary increase in transmission power, and it is possible to contribute to the solution of the true perspective problem.

  In this embodiment, in order to easily obtain the transmission power control timing, the temporary transmission power of the mobile station 1 is used in order to use the PILOT signal provided near the head of one slot in the call channel. Although the control is performed when the PILOT signal is transmitted, it can be performed when another signal is transmitted. However, in this case, the transmission power control timing given to the transmission output control unit 25 in the mobile station 1 may be the timing of the other signal.

  Further, in this embodiment, the signal for increasing the transmission power and the correlation value measurement target signal are determined in advance, but it is also possible to make them coincide by exchanging these pieces of information as control signals. However, since an increase in the control signal is generally not preferable, it is preferable to determine in advance. When AGC (Auto Gain control) is performed to suppress the influence of fading in the base station 26, timing information at which the transmission power of the mobile station 1 temporarily increases in the base station 26 in this way. Is preferably provided to a control means for performing auto gain control.

  In the present embodiment, the signal used to perform normal transmission power control for SIR equalization (the signal expressed by “11”) is the signal of the mobile station corresponding to the correlation value measurement target. The signal is also used as a signal for performing control for further increasing the transmission power, but it can also be realized by separately generating a signal for starting such partial transmission power increase control.

  In this embodiment, the estimated value of SIR is used in particular for determining the quality of the signal. However, if the quality is determined based on the signal after despreading using the obtained spreading code phase, other It is also possible to use the value of as a reference. (Supplementary note 1) In a spread spectrum communication system including a transmitter and a receiver that perform communication by transmitting and receiving a spread spectrum signal, the receiver obtains a spread code phase of the spread spectrum signal from the transmitter. The transmitter uses the spread spectrum signal transmitted to the receiver to obtain the spread code phase level of the spread spectrum signal of the portion used by the receiver acquisition means to acquire the spread code phase. A spread spectrum communication system, comprising: transmission power control means for performing transmission power control that is higher than a level of a spread spectrum signal of a portion not used. (Supplementary Note 2) In a spread spectrum communication system including a transmitter and a receiver that perform communication by transmitting and receiving a spread spectrum signal, the receiver obtains a spread code phase of the spread spectrum signal from the transmitter. And request means for requesting the transmitter to start transmission power control. Upon receiving the request, the transmitter transmits a spread spectrum signal to be transmitted to the receiver for a predetermined time. Among these, the transmission power control is performed so that the level of the spread spectrum signal of the portion used for acquiring the spread code phase by the acquisition means of the receiver is higher than the level of the spread spectrum signal of the portion not used for acquiring the spread code phase. A spread spectrum communication system comprising transmission power control means. (Appendix 3) Receiving spread spectrum signals from a plurality of transmitters, obtaining a spread code phase of the spread spectrum signal, despreading the spread spectrum signal using the spread code phase, A transmission power control signal for performing transmission power control so that the signal quality of the signal after despreading matches the signal quality after despreading of the spread spectrum signal from the other transmitter to the transmitter that transmitted the signal And a transmitter that transmits a spread spectrum signal to the receiver and controls the transmission power according to the transmission power control signal when the transmission power control signal is received. In the system, when the transmitter receives the transmission power control signal, the transmitter increases the reception power for a certain time when the transmission power is increased by the signal. Transmission power control means for further performing transmission power control for increasing the level of the spread spectrum signal of the part used for acquiring the spread code phase compared to the level of the spread spectrum communication signal of the part not used for obtaining the spread code phase A spread spectrum communication system characterized by comprising: (Additional remark 4) In the receiver which receives a spread spectrum signal, the acquisition means which acquires the spreading | diffusion code phase information of the received spread spectrum signal using the signal of the part by which transmission power was raised among the received spread spectrum signals A receiver comprising: (Supplementary Note 5) A transmitter for transmitting a spread spectrum signal has transmission power control means for performing transmission power control for transmitting a predetermined signal by increasing the transmission power from a level outside the predetermined signal when transmitting the predetermined signal. And transmitter. (Additional remark 6) In this invention, in the spread spectrum communication system containing the transmitter and receiver which communicate by transmitting / receiving a spread spectrum signal, this receiver is the spreading code phase of the spread spectrum signal from this transmitter. The transmitter has an acquisition means for acquiring the spread code phase of the spread spectrum signal transmitted to the receiver, the level of the signal used by the receiver acquisition means for acquiring the spread code phase. A spread spectrum communication system characterized by having transmission power control means for performing transmission power control to be higher than the signal level not used in the above.

  In the present invention, in a spread spectrum communication system including a transmitter and a receiver that communicate by transmitting and receiving a spread spectrum signal, the receiver acquires a spread code phase of the spread spectrum signal from the transmitter. And a requesting means for requesting the transmitter to start transmission power control. When the transmitter receives the request, the transmitter transmits a spectrum to the receiver for a predetermined time. Transmission power control means for performing transmission power control for increasing the level of the signal used by the receiver acquisition means for acquiring the spread code phase compared to the level of the signal not used for acquisition of the spread code phase among the spread signals. A spread spectrum communication system characterized in that it is used was used.

  Further, in the present invention, the spread spectrum signals from a plurality of transmitters are received, the spread code phase of the spread spectrum signal is acquired, the spread spectrum signal is despread using the spread code phase, Transmission for performing transmission power control so that the signal quality of the signal after despreading matches the signal quality after despreading of the spectrum spread signal from another transmitter to the transmitter that has transmitted the spread spectrum signal A receiver that transmits a power control signal; and a transmitter that transmits a spread spectrum signal to the receiver and controls transmission power according to the transmission power control signal when the transmission power control signal is received. In a spread spectrum communication system, when the transmitter receives the transmission power control signal, the transmitter increases the transmission power with the signal. And a transmission power control means for further performing transmission power control for increasing the level of the signal used by the receiver for acquiring the spreading code phase as compared with the level of the signal not used for acquiring the spreading code phase. A spread spectrum communication system is used.

  Further, in the present invention, a receiver that receives a spread spectrum signal acquires spread code phase information of the received spread spectrum signal using a signal of a portion of the received spread spectrum signal that has increased transmission power. A receiver characterized by having acquisition means was used. Further, in the present invention, in a transmitter that transmits a spread spectrum signal, when transmitting a predetermined signal, transmission power control for performing transmission power control for transmitting by increasing the transmission power from the level of a signal outside the predetermined signal A transmitter characterized by having means was used.

  In the present invention, the receiver receives the spread spectrum signal transmitted from the transmitter, and acquires the code spread phase of the received spread spectrum signal by the acquisition means. On the other hand, among the spread spectrum signals transmitted to the receiver by the transmission power control means, the transmitter uses the level of the signal that the receiver uses to acquire the spread code phase for acquiring the spread code phase. Transmission power control is performed so as to be higher than the level, and a spectrum spread signal subjected to this transmission power control is transmitted.

  In the present invention, the receiver receives the spread spectrum signal transmitted from the transmitter, and acquires the spread code phase of the received spread spectrum signal by the acquisition means. Further, the notification means requests the transmitter to start transmission power control. On the other hand, when the transmitter receives a request to start transmission power control from the receiver, the receiver uses the spread code phase among the spread spectrum signals transmitted to the receiver for a certain period of time by the transmission power control means. Transmission power control is started so that the level of the signal used for acquisition of the signal becomes higher than the level of the signal not used for acquisition of the spread code phase, and the spread spectrum signal subjected to this transmission power control is transmitted.

  In the present invention, the receiver acquires the spread code phase of the received spread spectrum signal, despreads the spread spectrum signal using the spread code phase, and transmits the spread spectrum signal to the transmitter that has transmitted the spread spectrum signal. By transmitting a transmission power control signal for performing transmission power control so that the quality of the signal after despreading matches the signal quality after despreading of the spread spectrum signal from another transmitter, The signal quality of the spread spectrum signal transmitted from each transmitter is made uniform. On the other hand, the transmitter performs transmission power control for equalizing signal quality from the receiver using a transmission power control signal, and when increasing the transmission power by this transmission power control, the transmitter is Among the spread spectrum signals to be transmitted, transmission power control is also performed so that the level of the signal used by the receiver to acquire the spreading code phase is higher than the level of the signal not used to acquire the spreading code phase. The spread spectrum signal subjected to the transmission power control is transmitted.

  In the present invention, the receiver that receives the spread spectrum signal uses the signal of the portion of the spread spectrum signal that has received the spread code phase of the received spread spectrum signal and the transmission power of which is increased by the acquisition means. get. In the present invention, the transmitter / receiver that transmits the spread spectrum signal performs control to increase the transmission power from the level of the signal that is not the predetermined signal when the predetermined signal is transmitted by the transmission power control means. A spread spectrum signal subjected to such transmission power control is transmitted. (Supplementary note 7) According to the present invention, the transmitter can control the start timing of the transmission by increasing the signal level of the predetermined portion by the receiver, and the transmitter can control the transmission power after a predetermined time has elapsed. Therefore, not only can the above-mentioned effects be achieved, but also interference with other transmitters can be further reduced. Moreover, the load accompanying the increase in the transmission power of the transmitter can be minimized.

  In addition, according to the present invention, the receiver performs despreading of the spread spectrum signal received using the acquired spread code phase, and the signal quality after the despreading is despread of the spread spectrum signal from another transmitter. A transmission power control instruction is issued to the transmitter that has transmitted the spread spectrum signal so as to align with the later signal quality. On the other hand, the transmitter performs transmission power control for equalizing the signal quality as instructed, and the signal level used by the receiver for acquiring the spreading code phase is higher than the signal level not used for acquiring the spreading code phase. The transmission power control is also increased.

  As a result, the receiver can acquire the spreading code phase at high speed and with high accuracy, and can efficiently perform despreading using the spreading code phase. Therefore, transmission power control based on the signal quality of the signal after the despreading is appropriate, the phenomenon of performing unnecessary transmission power control is reduced, and interference with other transmitters can be reduced. Therefore, the true perspective problem can be solved.

  In addition, since a transmission power control signal for equalizing quality is used, there is no need to increase the amount of control signal, and therefore an increase in interference with other transmitters due to an increase in control signal can be prevented.

1 shows a spread spectrum communication system tem according to the present invention. 1 shows a spread spectrum communication system tem according to the present invention. The structure of the framing part 29 concerning this invention is shown. The structure of the framing part 19 concerning this invention is shown. 1 illustrates a conventional spread spectrum communication system tem. 1 illustrates a conventional spread spectrum communication system tem. A delay profile is shown. The configuration of the framing unit 29 is shown. A configuration of the framing unit 19 is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Mobile station 2 Antenna 3 High frequency amplifier 4 Frequency converter 5 Demodulator 6 A / D converter 7 RAKE receiver 8 Correlator 9 Spread code generator 10 Phase controller 11 Controller 12 Searcher 13 Coder / decoder 14 A / D Converter 15 Microphone 16 D / A converter 17 Speaker 18 Timing control unit 19 Framing unit 20 Spreading unit 21 D / A converter 22 Modulator 23 Frequency converter 24 Variable gain amplifier 25 Transmission power control unit 26 Base station 27 SIR Estimating unit 28 SIR determining unit 29 Framing unit 30 Combining unit 185 Control unit

Claims (3)

In a mobile communication system including a transmitter and a receiver that perform communication by transmitting and receiving a transmission data that is subject to transmission power control and a signal in which a pilot signal is time-multiplexed,
The receiver has phase detection means for performing phase detection on the pilot signal transmitted from the transmitter,
When the transmitter performs transmission power change control based on the transmission power control signal received from the receiver, the transmission power control increases the level of the pilot signal relative to the level of the transmission data. Transmission power control means for performing
A mobile communication system. In a transmitter that transmits a transmission data that is subject to transmission power control and a signal in which a pilot signal is time-multiplexed,
Transmission power control for performing transmission power control for increasing the level of the pilot signal compared to the level of the transmission data when performing transmission power change control based on the transmission power control signal received from the receiver Having means,
A transmitter characterized by that. In a receiver that receives transmission data that is subject to transmission power control and a signal in which a pilot signal is time-multiplexed,
Transmitting means for transmitting a transmission power control signal to the transmitter of the signal source;
Receiving means for receiving a signal whose transmission power has been changed based on the transmission power control signal;
Phase detection means for performing phase detection on the pilot signal whose transmission power is higher than that of the transmission data among the signals received by the reception means;
A receiver comprising:

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