JP2005167475A - Receiver - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a receiver realizing optimal power consumption and receiving performance depending on the utilization purpose and the requiring performance. <P>SOLUTION: A control circuit 13 calculates an evaluation value H concerning a communication purpose, the receiving state of a received signal, and a detection system. When "delay detection" is selected based on the evaluation value H, a delay detection circuit 2 and a decision circuit 3 are operated and a select circuit 10 selects and outputs the output signal from the decision circuit 3. On the other hand, power supply or clock supply for operating a semi-synchronism detection circuit 4, a signal discriminator 6, and a differential decorder 7 is stopped. When "semi-synchronism detection" is selected based on the evaluation value H, the semi-synchronism detection circuit 4, the signal discriminator 6, and the differential decoder 7 are operated and the select circuit 10 selects and outputs the output signal from the differential decoder 7. On the other hand, power supply or clock supply for operating the delay detection circuit 2 and the decision circuit 3 is stopped. When "dynamic control of detection system " is selected based on the evaluation value H, they are switched dynamically during communication. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a receiver that demodulates a received signal.

  Conventionally, no received signal processing method has been developed that realizes the best reception performance with the minimum power consumption under any conditions. Therefore, for example, when receiving a π / 4 shift QPSK (Quadrature Phase Shift Keying) signal or a QAM (Quadrature Amplitude Modulation) signal, a receiver using delay detection or synchronous detection is a typical detection method. However, these two processing methods have characteristic differences as shown in Table 1 below.

  Conventionally, in order to solve such a problem, an adaptive receiver that selects a detection method according to a reception state of a received signal has been proposed as in each method shown in Table 2 below (for example, (See Patent Document 1, Patent Document 2, and Patent Document 3.)

In the case of a receiver that receives a CDMA (Code Division Multiple Access) signal or a spread spectrum signal, the number of fingers to be operated is changed according to the reception state of the received signal in a rake receiver having a plurality of fingers. Thus, power consumption is reduced (for example, Patent Document 4 and Patent Document 5).
JP 08-232232 A Japanese Patent Laid-Open No. 07-23072 Japanese Patent No. 2977396 JP-A-11-261523 JP 2000-252896 A

  By the way, in the receiver as described above, in view of the request contents of the user who uses the receiver, obtaining the highest reception performance is not necessarily the most profitable for the user. There was no problem. Specifically, in the case of the receivers described in Patent Document 1 and Patent Document 2, since two reception systems operate simultaneously, the battery life is greatly sacrificed in order to obtain the best reception performance. If the user's most desired request is stable reception processing with the best reception performance, there is no problem, but if the user's most desired request is to extend battery life, the two reception methods can be used simultaneously. There is a problem that operating and sacrificing battery life is against the user's interest.

  On the other hand, in the technique described in Patent Document 3 in which power consumption is taken into account, in order to determine whether to use a delay detection circuit or a quasi-synchronous detection circuit at the time of reception, the amount of intersymbol interference or signal determination error is always determined. The reception status of the received signal is monitored, but if the user's most desired request is not a stable reception process with the best reception performance but an extension of the battery life, the reception status of the received signal is monitored. There is a problem that the operation becomes redundant processing and consumes unnecessary power, which is contrary to the benefit of the user.

  Further, in the techniques described in Patent Document 4 and Patent Document 5, in a rake receiver having a plurality of fingers, power consumption is reduced by changing the number of fingers operating according to the reception state of the received signal. However, if the number of fingers operating in the rake receiver is excessive for the reception quality required by the user, unnecessary power will be consumed, which is against the user's interest. There was a problem.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a receiver that realizes optimum power consumption and reception performance according to the purpose of use and required performance.

  In order to solve the above-mentioned problem, a receiver according to the invention of claim 1 is a receiver that demodulates a received signal, and is a signal processing unit that processes the received signal by any of a plurality of processing methods ( For example, a delay detection circuit 2 and a quasi-synchronous detection circuit 4 in an embodiment to be described later, and an evaluation value calculation means for calculating an evaluation value according to the user's communication purpose (for example, a step executed by the control circuit 13 in the embodiment to be described later) S3) and determination means for selecting the processing method of the signal processing means based on the calculated evaluation value (for example, the process of step S5 executed by the control circuit 13 of the embodiment described later). Features.

  In the receiver having the above configuration, the determination unit determines the processing method of the signal processing unit according to the evaluation value according to the communication purpose of the user calculated by the evaluation value calculation unit. A signal can be received by a corresponding processing method.

  A receiver according to a second aspect of the present invention is the receiver according to the first aspect, further comprising reception state determination means for determining a reception state of the received signal (for example, a reception level detector 12 of an embodiment described later), The evaluation value calculating means calculates an evaluation value according to the communication purpose and the reception state.

  In the receiver having the above configuration, the evaluation value calculation means calculates an evaluation value corresponding to both the communication purpose of the user and the reception state of the received signal, and the determination means performs processing of the signal processing means according to the evaluation value. By determining the method, the signal can be received by a processing method balanced with both the user's communication purpose and the reception state of the received signal.

  A receiver according to a third aspect of the present invention is the receiver according to the second aspect, wherein the reception state determining means determines the reception state of the received signal before the start of the target communication or at the start of the target communication. It is characterized by being performed only for either.

  In the receiver having the above-described configuration, the reception state determination means performs the determination of the reception state of the received signal only before the start of the target communication to be executed by the user or at the start of the target communication. Thus, it is possible to reduce the processing load required for determining the reception state of the received signal.

  A receiver according to a fourth aspect of the present invention is the receiver according to the second aspect, wherein the reception state determining means intermittently determines the reception state of the received signal at predetermined intervals during communication, The evaluation value calculating means calculates an evaluation value corresponding to the communication purpose and the reception state at the same time.

  In the receiver having the above-described configuration, the reception state determination means intermittently performs the determination of the reception state of the reception signal at predetermined intervals during communication, so that the processing burden required for the determination of the reception state of the reception signal is reduced. It is possible to execute the determination of the reception state according to the actual received signal while reducing the above-mentioned, and at the same time, the evaluation value calculation means can calculate the optimum evaluation value for the determined reception state.

  A receiver according to a fifth aspect of the present invention is the receiver according to the first aspect, wherein the signal processing means receives a spread spectrum signal (for example, a rake receiver 23 in an embodiment described later). The judging means selects the number of fingers of the rake receiver.

  In the receiver having the above-described configuration, the determination unit selects the number of fingers of the rake receiver included in the signal processing unit, so that the signal can be rake-received with the number of fingers according to the user's communication purpose. it can.

  The receiver according to claim 6 is the receiver according to any one of claims 1 to 5, wherein the evaluation value calculation means uses the correction value based on a condition requested by the user. The evaluation value is weighted.

  In the receiver having the above configuration, the evaluation value calculation means weights the evaluation value using the correction value based on the condition requested by the user, so that the communication purpose of the user or the reception state of the received signal can be obtained. In addition, signals can be received by a processing method that takes into account the conditions required by the user, or by the number of fingers.

  A receiver according to a seventh aspect of the invention is characterized in that in the receiver according to the sixth aspect, the correction value can be set according to the communication purpose.

  In addition to the user's communication purpose or the reception status of the received signal, the receiver having the above configuration can further set a correction value based on the condition requested by the user according to the communication purpose. A signal can be received by a processing method that takes into account the conditions required for each user's communication purpose and the user's intention, or the number of fingers.

According to the receiver of the first aspect, a signal can be received by a processing method according to the communication purpose of the user.
Therefore, by using a processing method according to the user's communication purpose, the power consumption and reception performance are balanced, and both reception performance according to the user's communication purpose and prevention of unnecessary power consumption are achieved. The effect that it is realizable is acquired.

According to the receiver of the second aspect, the signal can be received by a processing method balanced with both the communication purpose of the user and the reception state of the received signal.
Therefore, by using a processing method according to the communication purpose of the user and the reception state of the received signal, the power consumption and the reception performance can be accurately balanced, so that the reception performance and the reception performance corresponding to the user's communication purpose can be reduced. An effect is obtained that both necessary prevention of power consumption can be realized accurately.

According to the receiver of the third aspect, it is possible to reduce the processing load required for determining the reception state of the received signal.
Therefore, the effect that unnecessary power consumption can be prevented can be achieved by reducing the processing load on the receiver.

According to the receiver of the fourth aspect, the evaluation value calculation means is determined by executing the determination of the reception state according to the actual reception signal while reducing the processing load required for the determination of the reception state of the reception signal. It is possible to calculate an evaluation value optimum for the reception state.
Therefore, by determining the reception state according to the actual reception signal, the power consumption and the reception performance are accurately balanced, so that the reception performance according to the user's communication purpose and unnecessary power consumption can be prevented. The effect that both can be realized is obtained. Further, by reducing the processing load on the receiver, unnecessary power consumption can be prevented.

According to the receiver of the fifth aspect, the signal can be rake-received by the number of fingers corresponding to the communication purpose of the user.
Therefore, by using the number of fingers according to the user's communication purpose, the power consumption and the reception performance are balanced, and both the reception performance according to the user's communication purpose and the prevention of unnecessary power consumption are achieved. The effect that it is realizable is acquired.

According to the receiver of the sixth aspect, in addition to the communication purpose of the user or the reception state of the received signal, the signal can be received by a processing method or a number of fingers that further considers a condition requested by the user. it can.
Therefore, it is possible to balance power consumption and reception performance according to the conditions required by the user, and to achieve both reception performance according to the user's communication purpose and conditions and prevention of unnecessary power consumption. An effect is obtained.

According to the receiver of claim 7, in addition to the user's communication purpose or the reception state of the received signal, a processing method that further considers the conditions required for each user's communication purpose and the user's intention Alternatively, the signal can be received by the number of fingers.
Therefore, the balance between power consumption and reception performance is optimized according to the conditions required by the user and the user's intention, so that reception performance according to the user's communication purpose and conditions and prevention of unnecessary power consumption are prevented. Both effects can be achieved accurately.

  Embodiments of the present invention will be described below with reference to the drawings.

(Receiver configuration)
FIG. 1 is a block diagram showing the configuration of the receiver according to the first embodiment of the present invention. It is assumed that the input signal to the receiver of this embodiment is subjected to differential encoding in order to perform delay detection. In addition, it is assumed that a known training signal section of signal length _NT is given to the received signal.
In FIG. 1, the receiver of the present embodiment is provided with a delay detection circuit 2 that delay-detects an RF frequency or IF frequency received signal input from an input terminal 1, and the output thereof is a delay detection circuit 2. Is connected to a determination circuit 3 that performs signal determination of a signal output from the signal. On the other hand, the receiver of the present embodiment is also provided with a quasi-synchronous detection circuit 4 for quasi-synchronously detecting the received signal of the input RF frequency or IF frequency. Cascade connection (cascade connection) signal determination unit 6 and differential decoder 7, and cascade connection (cascade connection) delay detector 8 and data determination unit 9 are connected in parallel.

Here, the signal determination unit 6 is a determination circuit that performs signal determination of the signal output from the quasi-synchronous detection circuit 4, and the differential encoding applied to the input signal for performing the delay detection is the signal determination unit 6. Is decoded by the differential decoder 7 connected to the output of the.
The delay detector 8 is a detector circuit that delay-detects the baseband signal output from the quasi-synchronous detector circuit 4. The data determiner 9 is the delay detector output from the delay detector 8 in the same manner as the determiner circuit 3. It is a determination circuit that performs signal determination of a subsequent signal (after decoding differential encoding).
The outputs of the determination circuit 3, the differential decoder 7, and the data determiner 9 are any one of the signals output from the determination circuit 3, the differential decoder 7, and the data determiner 9. A selection circuit 10 is connected to output from the output terminal 11 as an output signal of the receiver of this embodiment.

In addition, the receiver of the present embodiment is provided with a reception level detector 12 that measures the level (reception level R) of the received signal of the input RF frequency or IF frequency.
Furthermore, in order to select the optimum detection circuit for the communication purpose of the user, the receiver of this embodiment reads the reception level output from the reception level detector 12 and receives the communication purpose and the reception signal. In order to calculate the evaluation value H related to the state and the detection method, and to select the optimum detection circuit for the reception state of the received signal, the output of the delay detection circuit 2 and the output of the quasi-synchronous detection circuit 4 are read. In addition to calculating the intersymbol interference amount and the signal determination error for evaluating the reception state in each detection circuit, the selection circuit 10 and the switching device are based on the calculated evaluation value H, or the intersymbol interference amount and the signal determination error. 5 is provided with a control circuit 13 that selects an optimal detection circuit according to the communication purpose of the user and the reception state of the received signal.

  As a result, the receiver of this embodiment controls the selection circuit 10 and the switch 5 to input the received RF frequency or IF frequency received signal to the RF frequency or IF frequency by the delay detection circuit 2 and the determination circuit 3. The received RF frequency or IF frequency received signal is quasi-synchronously detected by the quasi-synchronous detection circuit 4, the signal decision unit 6 and the differential decoder 7, or the input RF frequency or IF After the received signal of the frequency is converted into a baseband signal by the quasi-synchronous detection circuit 4, it is possible to select whether to perform delay detection by the delay detector 8 and the data determiner 9, and to process the received signal.

In the receiver of the present embodiment, the delay detection circuit 2, the determination circuit 3, the quasi-synchronous detection circuit 4, the signal determination unit 6, the differential decoder 7, the delay detector 8, the data determination unit 9, and the reception level detector 12 may be realized by analog signal processing in which the received signal is processed as an analog value, or may be realized by digital signal processing in which the received signal is quantized and processed.
The control operation for selecting the optimum detection circuit by the control circuit 13 will be described later in detail.

(Control operation of control circuit)
Next, a control operation for selecting an optimum detection circuit by the control circuit 13 of the receiver according to the present embodiment will be described with reference to the drawings. First, a control operation for selecting an optimum detection circuit for a user's communication purpose will be described with reference to a flowchart. FIG. 2 is a flowchart showing a control operation in the control circuit 13 of the receiver of this embodiment.
In FIG. 2, the control circuit 13 of the receiver according to the present embodiment first determines whether or not to consider the reception state of the received signal when selecting the optimum detection circuit for the user's communication purpose. Is specified (step S1).

If it is specified in step S1 considering the reception state of the reception signal (YES in step S1), the control circuit 13 acquires the reception level R of the reception signal from the reception level detector 12 (step S2). .
Then, based on a control table stored in advance in the control circuit 13, an evaluation value H relating to the communication purpose, the reception state of the received signal, and the detection method is calculated (step S3).
On the other hand, when it is specified in step S1 that the reception state of the received signal is not considered (NO in step S1), the control circuit 13 sets “0” as the reception level R of the received signal (step S4). Proceeding to step S3, based on a control table stored in the control circuit 13 in advance, an evaluation value H relating to the communication purpose, the reception state of the received signal, and the detection method is calculated (step S3).

  Here, the control table stored in the control circuit 13 for calculating the evaluation value H related to the communication purpose, the reception state of the received signal, and the detection method will be described. Table 3 shown below shows the communication purpose of the user. Is a table showing a fixed profile set for each combination of the detection method and the detection method. The fixed profile is further determined by “reception level R <reception” depending on the reception level R of the received signal and the reception level threshold value Rth to be compared. The level threshold value Rth ”and the case of“ reception level R ≧ reception level threshold value Rth ”are divided into two. In Table 3, the larger the numerical value, the higher the required reception quality.

The “dynamic detection detection control” means that the detection circuit is dynamically switched during signal reception based on a determination value representing the received signal quality that is constantly calculated by the control circuit 13 during signal reception. This will be described later in detail.
In addition, for communication purposes of users, as an example of an application, an application that requires a relatively low reception quality such as normal voice by a cellular SELP codec or e-mail by text information, VOIP (Voice over There are applications that require a relatively high reception quality, such as voice by IP), and applications that have a very high reception quality, such as video. When the user's communication purpose is unspecified, it is handled as an application having a relatively high required reception quality so as not to affect the communication.

  Further, Table 4 shown below shows the user's request for each combination of the user's communication purpose and detection method in order to correct the fixed profile set for each combination of the user's communication purpose and detection method. The user request profile correction value set in consideration of the condition to be performed is shown. Specifically, in Table 4, for example, the conditions requested by the user are “extension of battery life” and “improvement of reception quality” as an example. Show. Hereinafter, in the documents, tables, and drawings, “extension of battery life” and “improvement of reception quality” are abbreviated as “battery life” and “reception quality”, respectively. Table 4 shows that the larger the numerical value, the more superior the user's request.

  Specifically, referring to Table 4, in applications where the required reception quality may be relatively low, such as e-mail using normal voice or text information, “delayed detection” is advantageous for “battery life”, so user requests On the other hand, the profile correction value “2” is designated. On the other hand, “dynamic detection control” is disadvantageous for “battery life”, so the user request profile correction value “−2” is designated. As for “reception quality”, since the application itself does not require high quality, there is no advantage in any detection method, and all “0” is designated.

  Further, Table 5 shown below is a table showing the user setting request magnification specified by the user according to personal preference with respect to the user request profile correction value set in Table 4, as shown in Table 5. For each combination of the communication purpose of the user and the condition requested by the user, a user setting request magnification that the user can freely set with a value of “0” to “5” for the user request profile correction value, for example. Can be specified. For example, in the example shown in Table 5, in applications where the required reception quality may be relatively low, such as e-mail using normal voice or text information, the “battery life” is given by the user to give priority to “battery life”. The user setting request magnification “4” is designated in the field of.

  Thereby, the evaluation value H related to the communication purpose, the reception state of the received signal, and the detection method is communicated according to the following equation (1) based on the control table stored in the control circuit 13 shown in Tables 3 to 5 in advance. The number of combinations of the purpose, the reception state of the received signal, and the detection method is calculated.

  However, in equation (1), P is a fixed profile, Q (n) is a user request profile correction value set by n types (n is a positive integer), and R (n) is an n type user request profile correction value. The corresponding user setting request magnification is indicated, and J is the total number of user request profile correction values. In this embodiment, there are two types of user request profile correction values related to “battery life (n = 1)” and “reception quality (n = 2)”, so the total number J of user request profile correction values is “J = 2”. Is. For example, in an application where the required reception quality may be relatively low, such as e-mail using normal voice or text information, when “reception level R <reception level threshold Rth”, “delay The final evaluation value H for “detection” is fixed profile P = 2, user request profile Q (1) = 2, Q (2) = 0, user setting request magnification R (1) = 4, R (2) = As 0, it is calculated as in the following equation (2).

On the other hand, when the evaluation value H can be calculated, the control circuit 13 selects an optimal detection circuit based on the calculated evaluation value H (step S5). Specifically, among the evaluation values H calculated by the above equation (1) shown in Table 6 below as an example, the detection method having the maximum evaluation value H among the evaluation values H according to the communication purpose requested by the user. And the selection circuit 10 and the switch 5 are controlled, and the output of the determination circuit of the signal connected to the detection circuit corresponding to the selected detection method is used as the output signal of the receiver of this embodiment.
Further, the control circuit 13 was not selected for power saving by stopping the power supply or the clock supply for operating the detection circuit and the signal determination circuit corresponding to the detection method that was not selected. The operation of the detection circuit and the signal determination circuit corresponding to the detection method is stopped (step S6).

  Specifically, referring to Table 6, in the case of an application where the required reception quality may be relatively low, such as e-mail using normal voice or text information by a cellular SELP codec, Whether level R <reception level threshold Rth ”or“ reception level R ≧ reception level threshold Rth ”,“ delay detection ”is selected as the detection method with the highest evaluation value H. On the other hand, in the case of an application having a relatively high required reception quality such as voice by VOIP (Voice over IP), when “reception level R <reception level threshold Rth”, the detection value with the maximum evaluation value H is used. When “dynamic control of detection method” is selected and “reception level R ≧ reception level threshold value Rth”, “quasi-synchronous detection” is selected as the detection method with the maximum evaluation value H.

  When “delay detection” is selected as the detection method with the maximum evaluation value H, the control circuit 13 operates the delay detection circuit 2 and the determination circuit 3 and selects the output signal of the determination circuit 3 in the selection circuit 10. And it outputs from the output terminal 11 as an output signal of the receiver of a present Example. On the other hand, the control circuit 13 stops the power supply or the clock supply for operating the quasi-synchronous detection circuit 4, the signal determination unit 6, and the differential decoder 7, thereby reducing the power consumption. The operations of the circuit 4, the signal determiner 6, and the differential decoder 7 are stopped.

  When “quasi-synchronous detection” is selected as the detection method with the maximum evaluation value H, the control circuit 13 operates the quasi-synchronous detection circuit 4, the signal determination unit 6, and the differential decoder 7 to select the selection circuit. 10, the output signal of the differential decoder 7 is selected and output from the output terminal 11 as the output signal of the receiver of this embodiment. On the other hand, the control circuit 13 stops the operation of the delay detection circuit 2 and the determination circuit 3 in order to save power by stopping the power supply or the clock supply for operating the delay detection circuit 2 and the determination circuit 3. To do.

  When “detection method dynamic control” is selected as the detection method with the maximum evaluation value H, the control circuit 13 performs the following operation. Note that the delay detector 8 and the data determination unit 9 are supplied with power or a clock for operation only when used in the following “dynamic detection detection control”.

(Dynamic detection control)
Next, the dynamic control operation of the detection method by the control circuit 13 of the receiver of this embodiment will be described.
The control circuit 13 receives the output signal of the delay detection circuit 2 and the output signal of the quasi-synchronous detection circuit 4, and selects the better one of the delay detection circuit 2 and the quasi-synchronous detection circuit 4 for each switching timing. And make it work. Further, the control circuit 13 controls the selection circuit 10 to select an output signal of the determination circuit 3 or the differential decoder 7 and further to the data determination unit 9 as an output signal of the receiver of this embodiment. Output from the output terminal 11.
In the following description, the modulation scheme is assumed to be differentially encoded QPSK, and the signal sampling period is assumed to be the symbol period T of the modulated wave. In addition, all signals are expressed using a complex display having an in-phase component in the real part and a quadrature component in the imaginary part.

  First, the delay detection circuit 2 and the determination circuit 3 are already selected and operated, and the output signal of the determination circuit 3 is selected by the selection circuit 10 and is output from the output terminal 11 as the output signal of the receiver of this embodiment. The control circuit 13 obtains the amount of intersymbol interference included in the output signal of the delay detection circuit 2. The intersymbol interference amount is a physical quantity representing the degree of waveform distortion due to intersymbol interference. When this value is large, the quasi-synchronous detection circuit 4, the signal determination unit 6, and the reception processing by the delay detection circuit 2 and the determination circuit 3 It can be determined that the reception processing by the differential decoder 7 is more suitable for reception. Therefore, when the amount of intersymbol interference exceeds a preset threshold value, control is performed to switch to the reception processing by the quasi-synchronous detection circuit 4, the signal determination unit 6, and the differential decoder 7 at the switching timing. For example, when the switching timing is set to burst timing, the control circuit 13 operates the quasi-synchronous detection circuit 4, the signal determination unit 6, and the differential decoder 7 at the next burst timing to control the selection circuit 10. Thus, the output signal of the differential decoder 7 is selected and output from the output terminal 11 as the output signal of the receiver of this embodiment.

The sampling value of the signal output from the delay detection circuit 2 at time t = kT (k is an integer) is z (k), and the phase difference between the complex symbols at time t = kT and time (k−1) T is d ( k), when a waveform distortion due to intersymbol interference occurs, a correlation appears in z (k) d ^* (k) and d (k−1). Here, * represents a complex conjugate. Therefore, the intersymbol interference amount can be calculated as a correlation amount between z (k) d ^* (k) and d (k−1). For example, if the designated signal interval is a training signal interval of signal length _NT where d (k) is known, this correlation ρ is given by the following equation (3).

On the other hand, the quasi-synchronous detection circuit 4, the signal determination unit 6, and the differential decoder 7 are already selected and operated, and the output signal of the differential decoder 7 is selected by the selection circuit 10, and the output of the receiver of this embodiment is output. When outputting from the output terminal 11 as a signal, the control circuit 13 determines from the output signal of the delay detection circuit 2 and the output signal of the quasi-synchronous detection circuit 4 based on the determination formula obtained from the signal determination error indicating the reception quality. Of the delay detection circuit 2 and the quasi-synchronous detection circuit 4, the one that seems to have good BER (Bit Error Rate) characteristics is selected.
Specifically, if the same BER is obtained in the delay detection method and the synchronous detection method, the S / N ratio (Signal to Noise Ratio) of the signal at the output of the detection circuit, or the signal energy to noise power per bit. The density E _b / N ₀ may be the same. Therefore, for example, by the following equation (4), the signal determination error for the output signal of the delay detection circuit 2 is compared with the signal determination error for the output signal of the quasi-synchronous detection circuit 4 in the known training signal interval of the signal length _NT. By doing so, it is possible to select one of the delay detection circuit 2 and the quasi-synchronous detection circuit 4 that seems to have good BER characteristics.

In the above equation (4), e _D (k) is a signal determination error for the output signal of the delay detection circuit 2, and e _E (k) is a signal determination error for the output signal of the quasi-synchronous detection circuit 4. . When the determination value D is negative, at the next burst timing, the control circuit 13 operates the delay detection circuit 2 and the determination circuit 3 and controls the selection circuit 10 to select the output signal of the determination circuit 3. , And output from the output terminal 11 as an output signal of the receiver of this embodiment. On the other hand, when the determination value D is positive, the control circuit 13 operates the quasi-synchronous detection circuit 4, the signal determination unit 6, and the differential decoder 7, and controls the selection circuit 10 to control the differential decoder 7. The output signal is selected and output from the output terminal 11 as the output signal of the receiver of this embodiment.

  In addition, the quasi-synchronous detection circuit 4, the signal determination unit 6, and the differential decoder 7 are already selected and operated, and the output signal of the differential decoder 7 is selected by the selection circuit 10, and the output of the receiver of this embodiment is output. When the control circuit 13 changes the detection method to delay detection based on the determination value D when outputting from the output terminal 11 as a signal, first the delay detector 8 and the data determination unit 9 are operated, and the selection circuit 10 And the output signal of the data decision unit 9 is selected and output from the output terminal 11 as the output signal of the receiver of this embodiment, and the delay detection circuit 2 and the decision circuit 3 are operated at the next burst timing. Then, the selection circuit 10 may be controlled to select the output signal of the determination circuit 3 and output from the output terminal 11 as the output signal of the receiver of this embodiment.

  For example, in a mobile radio communication system, the mobile station apparatus moves, so that the delay dispersion of the propagation path greatly fluctuates and the reception state of the received signal also changes from time to time. However, as described above, the detection system is dynamically switched. When controlling, the reception status of the received signal is always monitored, and the signal can be processed by constantly switching to the detection method that is optimal for the received status of the received signal. Even in the case of using, there is an effect that the power consumption of the apparatus can be reduced as much as possible while maintaining high reception quality of a certain level or higher.

  In the above-described embodiment, when the control circuit 13 calculates the evaluation value H related to the communication purpose, the reception state of the received signal, and the detection method, the fixed profile shown in Table 3 is received as an index indicating the reception state. Depending on the reception level R of the signal and the reception level threshold value Rth to be compared, there are two types of cases: reception level R <reception level threshold value Rth and reception level R ≧ reception level threshold value Rth. In Table 6, the evaluation value H was classified and calculated according to the reception level R of the received signal and the reception level threshold value Rth to be compared in Table 6. However, as shown in Table 7 below, The delay time T of the received signal and the delay time threshold value Tth to be compared as an index indicating the reception state, when delay time T <delay time threshold value Tth, and delay time T ≧ delay time Set by dividing into two as in the threshold Tth, it may be calculated by classifying the evaluation value H by a delay time threshold Tth as the compared with the delay time T of the received signal.

Further, the delay time T of the received signal can be calculated from the received time of the training signal having a known signal length _NT . Therefore, in that case, the reception level detector 12 may not be provided in the receiver of the present embodiment.

  As described above, the detection method selection operation for the communication purpose of the user shown in steps S1 to S6 in FIG. 2 does not need to be performed in real time, and the target communication is particularly completed in a short time. In this case, it is sufficient that the detection method is determined at least before the start of the target communication. Therefore, for example, the determination of the reception state by the reception level detector 12 does not need to be executed in real time, and may be executed only before the start of the target communication or at the start of the target communication. Thereby, it is possible to reduce power consumption and processing capacity required for the circuit.

  Note that “target communication” here refers to communication by an application as shown in Tables 3 to 7 above as the communication purpose of the user, and a state in which both sides can communicate between the transceivers. The communication related to transmission / reception of the control signal executed for holding the signal is always or appropriately executed as long as power is supplied to the transmitter and the receiver. Therefore, the receiver according to the present embodiment receives the reception signal when receiving the control signal from the transmitter when the reception level detector 12 determines the reception state before the start of the target communication or at the start of the target communication. What is necessary is just to judge a state.

  However, if the target communication does not end in a short time, for example, in the mobile radio communication system, the mobile station apparatus moves with the user, so that the reception state changes greatly. Therefore, from step S1 to step S6 in FIG. The processing shown in FIG. 5 may be executed intermittently at predetermined intervals, and the reception state may be periodically reviewed to select the optimum detection method (detection circuit). As a result, the reception status of the received signal can be received according to the actual received signal while reducing the processing load required for determining the received status of the received signal by intermittently determining the received status of the received signal at predetermined intervals during communication. It is possible to calculate the evaluation value H optimum for the reception state determined at the same time by executing the determination of the state. Therefore, by determining the reception state according to the actual reception signal, the power consumption and the reception performance are accurately balanced, so that the reception performance according to the user's communication purpose and unnecessary power consumption can be prevented. The effect that both can be realized accurately is obtained. Further, by reducing the processing load on the receiver, unnecessary power consumption can be prevented.

  In this embodiment, the control circuit 13 includes evaluation value calculation means and determination means. More specifically, step S3 in FIG. 2 corresponds to the evaluation value calculation means, and step S5 in FIG. 2 corresponds to the determination means.

As described above, according to the receiver of this embodiment, the evaluation value H related to the communication purpose, the reception state of the received signal, and the detection method is calculated based on the control table stored in advance in the control circuit 13. In addition, the detection method is selected based on the calculated evaluation value H, and the detection circuit corresponding to the selected detection method is operated, so that both the communication purpose of the user and the reception state of the received signal are balanced. A signal can be received by a processing method.
Therefore, by using a processing method that balances both the communication purpose of the user and the reception state of the received signal, the power consumption and the reception performance are balanced, and the reception performance corresponding to the user's communication purpose is reduced. It is possible to achieve both the necessary power consumption prevention.

  In applications where the target communication can be expected to be completed in a short time, the reception level detector 12 determines the reception state only before the start of the target communication or at the start of the target communication, By ending the detection method selection operation for the communication purpose of the person at least before the start of the target communication, it is possible to reduce the power consumption and the processing capacity required for the circuit.

  On the other hand, in applications where the target communication can be assumed not to be completed in a short time, the reception level detector 12 periodically performs determination of the reception state, and at the same time, performs a detection method selection operation for the user's communication purpose. By selecting the optimum detection method (detection circuit) for the determined reception state, the reception state corresponding to the actual reception signal is reduced while reducing the processing load required to determine the reception state of the reception signal. The effect that it is possible to accurately realize both the reception performance according to the user's communication purpose and the prevention of unnecessary power consumption by accurately balancing power consumption and reception performance. Is obtained. Further, by reducing the processing load on the receiver, unnecessary power consumption can be prevented.

  Further, when calculating the evaluation value H, in order to reflect the condition requested by the user in the selection of the detection method, the condition requested by the user and the user's By quantifying the intention and reflecting it in the evaluation value H, the balance between power consumption and reception performance is optimized according to the condition requested by the user and the intention of the user, and according to the communication purpose and condition of the user. Thus, it is possible to accurately achieve both the reception performance and the prevention of unnecessary power consumption.

(Receiver configuration)
FIG. 3 is a block diagram showing the configuration of the receiver according to the second embodiment of the present invention. Note that it is assumed that the input signal to the receiver of this embodiment is spread spectrum. In addition, it is assumed that the spread code used when performing spread spectrum on the transmission side is already known on the receiver side. Further, the transmission side transmits a synchronization signal for synchronizing the timing of signal transmission / reception between the transmitter and receiver so that the receiver finds the head signal of the received signal. This synchronization signal is also known on the receiver side. It shall be.

  In FIG. 3, the receiver of the present embodiment is provided with a rake receiving unit 23 including a path searcher 21 and a plurality of fingers 22-1 to 22-3. For simplification of explanation, in this embodiment, the number of fingers provided in the rake receiving unit 23 is three, and the fingers are shown as fingers 22-1 to 22-3. Can be reduced or increased. The path searcher 21 receives a reception signal frequency-converted into a baseband signal by the frequency converter 24, and the path searcher 21 receives a reception timing of a multipath signal included in the reception signal from the reception signal. To extract. Specifically, a sliding correlator is provided, for example, calculating the correlation between the received signal and a replica of the synchronization signal that should have been transmitted from the base station while shifting the timing with respect to the received signal, and the correlation value is The timing at which it increases becomes the reception timing of the multipath signal included in the reception signal.

  That is, from the path searcher 21, the number (number of lines) matched to the plurality of fingers 22-1 to 22-3 provided in descending order of the correlation value at the timing when the correlation value equal to or greater than a certain threshold is calculated. In the embodiment, a maximum of three reception timings are selected and output, and are sequentially set to the plurality of fingers 22-1 to 22-3. Note that the reception timing is not set when the timing at which the correlation value equal to or greater than a certain threshold is calculated is small and the number of reception timings output from the path searcher 21 is less than the number of fingers provided. The finger stops its operation to save power by stopping the power supply or clock supply for operating the finger whose reception timing is not set by the control circuit 30 to be described later, and the reception processing at that time Shall not be involved.

  On the other hand, the fingers 22-1 to 22-3 are despreaders all having the same configuration, and each finger applies a spread code to the input received signal according to the reception timing set from the path searcher 21. The correlation value of both is calculated and the timing of the received signal and the spread code is sequentially shifted by the symbol period, and the correlation value of both is calculated, thereby demodulating the spread spectrum applied to the received signal. Converted to a signal.

Thereby, when the input received signal is a multipath signal, the signals of a plurality of paths constituting the multipath signal are each received by each finger that performs demodulation processing at the reception timing of the signal of each path. It is decomposed and extracted into a route signal. In this embodiment, as an example, the number of fingers is three, so that it is possible to extract signals of three waves that have arrived along different paths.
Further, the symbol signals output from the fingers 22-1 to 22-3 are added in the symbol combiner 25 in consideration of the reception timing shift of the received signals, whereby the multipath signals are rake combined.

Further, the output signal of the symbol synthesizer 25 is input to the demodulator 26, and the primary modulation, such as QPSK, performed on the transmission side is demodulated, and the convolutional encoding performed on the transmission side is decoded to generate an error. Correction and the like are performed and converted into received data.
On the other hand, in the symbol error rate calculation unit 27, the convolutional encoding performed on the transmission side is performed again on the received data, and the hard decision value of the symbol signal output from the symbol synthesizer 25 and the convolutional encoding are performed again. The received data is compared, and the degree of error that does not match, that is, the symbol error rate SER is calculated.

  The symbol error rate SER calculated by the symbol error rate calculation unit 27 is compared by the comparator 28 with the values R1 and R2 (where R1> R2) of the two registers 29-1 and 29-2, respectively. , “SER> R1> R2”, “R1> SER> R2”, and “R1> R2> SER” are output from the comparator 28 and input to the control circuit 30.

  It is assumed that the number of registers is one less than the number of fingers provided in the rake receiving unit 23, and in this embodiment, the case of three fingers is described as an example. Thus, the number of registers is two. Therefore, when the number of fingers is n (n = positive integer), the symbol error rate calculated by the symbol error rate calculation unit 27 is compared with the values of (n−1) registers in the comparator 28, respectively. Then, n types of comparison results are output from the comparator 28 and input to the control circuit 30.

  The control circuit 30 is a control unit that controls the operation of the rake receiving unit 23, and the rake receiving unit 23 performs a rake based on the comparison result between the symbol error rate SER output from the comparator 28 and the register value. Control the number of fingers that contribute to the synthesis. Specifically, when the comparison result output from the comparator 28 is “SER> R1> R2,” the reception state is not good, so the number of fingers contributing to rake synthesis in the rake receiving unit 23 is three. And When the comparison result output from the comparator 28 is “R1> SER> R2,” the number of fingers contributing to rake composition in the rake receiving unit 23 is two. When the comparison result output from the comparator 28 is “R1> R2> SER”, since the reception state is good, the number of fingers contributing to rake synthesis in the rake receiving unit 23 is one.

  Further, the control circuit 30 calculates an evaluation value H related to the user's communication purpose in order to select the optimum number of fingers for the user's communication purpose, and registers 29 based on the calculated evaluation value H. Control for changing the values R1 and R2 of −1 and 29-2 is executed. Also in this embodiment, as in the first embodiment, the control circuit 30 includes an evaluation value calculation means and a determination means, and the evaluation value calculation means sets the evaluation value H according to the user's communication purpose. In addition to calculating, the registers 29-1, 29 are selected so that the determination means selects the processing method of the signal processing means based on the calculated evaluation value H, that is, the number of fingers contributing to rake synthesis in the rake receiving unit 23. Control for changing the values R1 and R2 of -2.

(Control operation of control circuit)
Next, the control operation for selecting the optimum number of fingers by the control circuit 30 of the receiver of this embodiment will be described.
The control circuit 30 of the receiver according to the present embodiment first calculates an evaluation value H relating to the user's communication purpose based on a control table stored in the control circuit 30 in advance. Here, the control table stored in the control circuit 30 for calculating the evaluation value H related to the communication purpose, the reception state of the received signal, and the detection method will be described. Table 8 shown below shows the communication purpose of the user. It is a table | surface which shows the fixed profile set for every. In Table 8, the larger the numerical value, the higher the required reception quality.

  Here, for communication purposes of users, as examples of applications, e-mails using text information, etc., applications that may require a low reception quality, normal voices using cellular SELP codecs, etc. are required. Applications that require relatively low quality, applications that require a little higher reception quality such as high-quality audio with a higher bit rate than normal audio, and voice and video that are required by VOIP (Voice over IP), etc. There are relatively or fairly expensive applications. When the user's communication purpose is unspecified, it is handled as an intermediate between a required application with low reception quality and a high application so that communication is not affected.

  Table 9 shown below shows a user request profile set in consideration of the conditions required by the user for each user communication purpose in order to correct the fixed profile set for each user communication purpose. Specifically, in Table 9, for example, the conditions requested by the user are shown as “extension of battery life” and “improvement of reception quality”. In the present embodiment, “battery life extension” and “reception quality improvement” are abbreviated as “battery life” and “reception quality”, respectively, in the documents, tables, and drawings. Table 9 indicates that the larger the numerical value, the greater the number of fingers required for the user's request.

Specifically, referring to Table 9, in applications where the required reception quality may be low, such as e-mail using text information, it is better to reduce the number of fingers to prioritize “battery life”. When the request profile modification value “−1” is designated, and “reception quality” is prioritized, the user request profile modification value “0” is designated because the number of fingers is not excessively increased.
In applications where the required reception quality is relatively high or very high, such as voice and video by VOIP (Voice over IP), it is better to reduce the number of fingers in order to prioritize the “battery life”. When the correction value “−1” is designated, on the other hand, when “reception quality” is prioritized, the user request profile correction value “2” is designated because the number of fingers is to be increased as much as possible.

  Further, Table 10 shown below is a table showing the user setting request magnification specified by the user according to personal preference with respect to the user request profile correction value set in Table 9, as shown in Table 10. For each combination of the communication purpose of the user and the condition requested by the user, a user setting request magnification that the user can freely set with a value of “0” to “5” for the user request profile correction value, for example. Can be specified. For example, in the example shown in Table 10, in applications where the required reception quality may be low, such as e-mail using text information, the user sets the “Battery Life” column in the “Battery Life” column to give priority to “Battery Life”. The requested magnification “2” is designated.

  As a result, the evaluation value H relating to the user's communication purpose is calculated by the following equation (5) based on the control table stored in advance in the control circuit 30 shown in Tables 8 to 10 for the number of communication purposes. .

  However, in equation (5), P is a fixed profile, Q (n) is a user request profile correction value set by n types (n is a positive integer), and R (n) is an n type user request profile correction value. The corresponding user setting request magnification is indicated, and J is the total number of user request profile correction values. Also in this embodiment, since the user request profile correction values are two types relating to “battery life (n = 1)” and “reception quality (n = 2)”, the total number J of user request profile correction values is “J = 2”. Is. For example, in the case of an application where the required reception quality may be low, such as e-mail based on text information, the final evaluation value H is fixed profile P = −2, user request profile Q (1 ) = − 1, Q (2) = 0, user setting request magnification R (1) = 2, and R (2) = 0.

  On the other hand, when the evaluation value H can be calculated, the control circuit 30 further changes the values R1 and R2 of the registers 29-1 and 29-2 according to the following equation (7) based on the calculated evaluation value H. A correction value RH is calculated.

  Specifically, as an example, based on the evaluation value H calculated by the above formula (5) shown in the following Table 11, the register correction value RH calculated by the above formula (7) shown in the following Table 11 is also calculated. To do. Then, the values R1 and R2 of the registers 29-1 and 29-2 are changed according to the following equations (8) and (9). Note that the initial register values in equations (8) and (9) are arbitrarily determined based on the overall reception performance of the receiver when the receiver is designed.

R1 = register initial value × RH (8)

R2 = register initial value × RH (9)

Then, the control circuit 30 controls the symbol error rate SER output from the comparator 28 and the values of the registers 29-1 and 29-2 controlled so as to select the optimum number of fingers for the user's communication purpose. Based on the comparison results with R1 and R2, the number of fingers contributing to rake synthesis is controlled in the rake receiving unit 23.
In addition, the fingers that are not used for the rake synthesis are controlled by the control circuit 30 described later for power saving by stopping the power supply or the clock supply for operating the fingers that are not used for the rake synthesis. It is assumed that the operation is stopped and the reception process at that time is not involved.

  More specifically, referring to Table 11, for example, in an application where the required reception quality may be low, such as e-mail using text information, the register correction value RH≈316 is calculated. 29-2, even if the symbol error rate SER slightly deteriorates, the comparison result in the comparator 28 tends to be “R1> R2> SER”. The number of fingers contributing to the synthesis is one, and both reception performance according to the user's communication purpose and prevention of unnecessary power consumption can be realized.

  On the other hand, in applications where the required reception quality is relatively high or very high, such as voice and video by VOIP, the register correction value RH≈0.00316 is calculated, so the values R1 and R2 of the registers 29-1 and 29-2 are calculated. Even if the symbol rate SER is somewhat good, the comparison result in the comparator 28 is likely to be “SER> R1> R2,” so that the number of fingers contributing to the rake composition in the rake receiving unit 23 is three. Even if power consumption is sacrificed, it is possible to stably realize the reception performance according to the user's communication purpose.

As described above, according to the receiver of the present embodiment, the evaluation value H related to the communication purpose is calculated based on the control table stored in the control circuit 30 in advance, and based on the calculated evaluation value H. By selecting the number of fingers contributing to rake reception and operating the selected number of fingers, the signal can be rake-received with the number of fingers according to the user's communication purpose.
Therefore, by using the number of fingers according to the user's communication purpose, the power consumption and the reception performance are balanced, and both the reception performance according to the user's communication purpose and the prevention of unnecessary power consumption are achieved. The effect that it is realizable is acquired.

  Further, when calculating the evaluation value H, in order to reflect the condition requested by the user in the selection of the detection method, the condition requested by the user and the user's By quantifying the intention and reflecting it in the evaluation value H, the balance between power consumption and reception performance is optimized according to the condition requested by the user and the intention of the user, and according to the communication purpose and condition of the user. Thus, it is possible to accurately achieve both the reception performance and the prevention of unnecessary power consumption.

  The receiver of the present embodiment is not limited to the range of the above-described embodiment, but by increasing the number of detection methods that can be further selected in the detector of the receiver, it does not improve the performance as much as possible, but most satisfies the user's request. Realizing near power consumption and performance, it is possible to satisfy both reduction of unnecessary power consumption and maintenance of required performance.

It is a block diagram which shows the structure of the receiver of 1st Example of this invention. It is a flowchart which shows the control action in the control circuit of the receiver of the Example. It is a block diagram which shows the structure of the receiver of the 2nd Example of this invention. .

Explanation of symbols

1 input terminal 2 delay detection circuit (signal processing means)
3 Judgment circuit 4 Quasi-synchronous detection circuit (signal processing means)
DESCRIPTION OF SYMBOLS 5 Switch 6 Signal determination device 7 Differential decoder 8 Delay detector 9 Data determination device 10 Selection circuit 11 Output terminal 12 Reception level detector (reception state determination means)
13 Control Circuit 21 Path Searcher 22-1 to 22-3 Finger 23 Rake Receiver (Rake Receiver)
24 frequency converter 25 symbol synthesizer 26 demodulator 27 symbol error rate calculation unit 28 comparator 29-1, 29-2 register 30 control circuit S3 evaluation value calculation means S5 determination means

Claims (7)

A receiver that demodulates a received signal,
Signal processing means for processing the received signal by any of a plurality of processing methods;
An evaluation value calculating means for calculating an evaluation value according to the communication purpose of the user;
A receiver comprising: a determination unit that selects a processing method of the signal processing unit based on the calculated evaluation value. A reception state determination means for determining a reception state of the reception signal;
The receiver according to claim 1, wherein the evaluation value calculating unit calculates an evaluation value according to the communication purpose and the reception state. The receiver according to claim 2, wherein the reception state determination unit determines the reception state of the reception signal only before the start of the target communication or at the start of the target communication. The reception state determining means intermittently determines the reception state of the received signal at predetermined intervals during communication,
3. The receiver according to claim 2, wherein the evaluation value calculation means calculates an evaluation value corresponding to the communication purpose and the reception state at the same time. The signal processing means comprises a rake receiver for receiving a spread spectrum signal;
The receiver according to claim 1, wherein the determination unit selects the number of fingers of the rake receiver. The receiver according to claim 1, wherein the evaluation value calculation unit weights the evaluation value using a correction value based on a condition requested by the user. The receiver according to claim 6, wherein the correction value can be set according to the communication purpose.

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