JP2004356837A - Random access reception method and reception apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the consumed current of a battery by predicting a period when there is no possibility of receiving data thereby stopping the operation of a data decoding section. <P>SOLUTION: The random access receiver discriminates the propriety of a reception state of a signal from a base station and discriminates whether or not a likelihood value is smaller than a threshold value, the likelihood value being obtained by decode processing of a TFCI included in a secondary common control physical channel (SCCPCH) received from the base station, when the reception state is excellent and the likelihood value is smaller than the threshold value, a no-reception discrimination section 11 discriminates no reception interval to stop the operation of a decoding section 8 of a mobile station, and when the reception state is excellent and the likelihood value is greater than the threshold value or the reception state is bad, the no-reception discrimination section 11 activates the decoding section. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a random access receiving method and a receiving apparatus of a mobile station in a random access state in which communication is performed between a base station and a base station using a downlink common channel and an uplink common channel, and particularly conforms to the 3GPP standard such as a W-CDMA terminal apparatus. The present invention relates to a random access receiving method and a receiving apparatus for identifying a non-receiving section during random access in a wireless communication apparatus, cutting off power supply in the section, and saving power.
[0002]
[Prior art]
In the W-CDMA system, in order for a mobile terminal device to communicate with a base station device, first, a cell search is performed to identify a frame timing / slot timing and a scramble code of the base station, and then these identifications are performed. A connection process is performed between the mobile terminal device and the base station device using the information. That is, the connection processing between the base station device (actually, the network) and the terminal device is performed by the Secondary Common Control Physical Channel (hereinafter abbreviated as SCCPCH) which is a downlink common channel and the Physical Random Access Channel (hereinafter abbreviated as PRACH) which is an uplink common channel. I do. This state is a random access state and is called an access state (Access State).
[0003]
When the connection processing is completed according to the access state (Access State), the base station apparatus and the terminal apparatus individually perform communication using a dedicated physical channel (hereinafter, abbreviated as DPCH). This state is called an individual state (Dedicated State).
Further, in a state in which traffic increases and decreases discontinuously, such as in packet communication, when the traffic decreases, the state changes from the dedicated state (Dedicated State) to the access state (Access State), and when the traffic increases, the state changes again to the dedicated state (Dedicated State). By returning, it is possible to support a plurality of users with a minimum of radio resources.
[0004]
(A) Configuration of mobile station during random access
FIG. 11 is a configuration diagram during random access of a mobile station (mobile terminal device) in a W-CDMA system according to the 3GPP standard.
The wireless unit 1 converts a high-frequency reception signal into a baseband signal, performs AD conversion, and outputs the converted signal. In response to a channel transmission / reception request from the upper layer 9, the searcher 2 calculates the correlation between the spread code assigned to the mobile station and the received signal, detects the timing of each path of the multipath, and uses the timing for downlink common channel SCCPCH. Of the common pilot channel CPICH. Each of the despreading units 3 and 4 despreads the received signal at each input timing using a known code, and rake-combines the despread result at each timing and inputs the result to the demodulation units 5 and 6. As shown in FIG. 12, the SCCPCH frame includes TFCI, Pilot control signals and data Data in each of 15 slots # 0 to # 14 per frame (10 msec). The TFCI (encoded) is demodulated and output.
[0005]
The TFCI (Transmission Format Combination Indicator) is used to determine how to encode each transport channel TrCH so that when the encoded data of each transport channel TrCH is multiplexed and transmitted on the transmitting side, it can be correctly separated on the receiving side. This parameter indicates whether data has been multiplexed. On the transmitting side, a coding process is performed on the TFCI to create a TFCI Code Word (32-bit data), and the TFCI Code Word is transmitted. The TFCI decoder 7 decodes the TFCI from the TFCI Code Word and inputs the TFCI to the decoding unit 8. The decoding unit 8 performs a decoding process for each TrCH using the TFCI, and inputs a decoding result to the upper layer unit 9.
[0006]
In the above access state (Access State), when the mobile station MS moves away from the base station BTS to receive the downlink common channel SCCPCH, it is necessary to change the base station to a neighboring base station BTS. For this reason, it is necessary for the mobile station MS to periodically monitor the peripheral base station BTS, and this monitoring is performed based on a determination called S determination defined by 3GPP.
When there is a level measurement request from the upper layer unit 9, the demodulation unit 6 demodulates a pilot signal from the common pilot channel CPICH and inputs the demodulated pilot signal to the S determination unit 10. The S determination unit 10 determines whether or not to perform the measurement of the neighboring cell (adjacent cell) based on the signal level of the pilot. (1) If it is not necessary to perform the measurement (S determination is good), the measurement is not performed. 2) If measurement is necessary (S determination failure), the pilot signal level of the neighboring cell is measured and input to upper layer section 9. The upper layer unit 9 performs soft handoff control for changing the base station based on the pilot signal levels of the neighboring cells.
[0007]
The following is the determination algorithm of the S determination unit 10.
The measured cell quality value (received signal quality Ec / No of downlink common channel CPICCH) in the cell is Q _qualmeans , The minimum required quality level of the cell being Qqualmin,
Squal = Q _qualmeans -Qualmin
Is calculated by the following equation. Then, Squal and Sintrasearch and Sintersearch specified from the upper level are compared,
If Squal> Sintrasearch, the adjacent cell is not measured for the same frequency cell (S judgment is good). However, if Squal ≦ Sintrasearch, the adjacent cell is measured for the same frequency cell, and the measurement level is input to the upper layer unit 9 (S determination failure). Also,
If Squal> Sintersearch, the adjacent cell is not measured for the different frequency cell (S determination is good). However, if Squal ≦ Sintersearch, the adjacent cell is measured for the different frequency cell, and the measurement level is input to the upper layer unit 9 (S determination failure).
[0008]
(B) TFCI
In W-CDMA, the transmission time interval TTI (Transmission Time Interval) is defined as 10 ms, 20 ms, 40 ms, and 80 ms as shown in FIG. 13, and becomes 1 TTI in 1, 2, 4, and 8 frames, respectively. The data is encoded. For example, if the transport channel TrCH has a TTI of 40 ms, four frames are encoded as one unit. Then, the encoded data of each TrCH is multiplexed in units of 10 msec and transmitted.
The TFCI is a parameter indicating how the coded data of each TrCH is multiplexed so that the coded data of each TrCH can be correctly separated on the receiving side when the coded data of each TrCH is multiplexed and transmitted. That is, the TFCI is a bit length per TTI of the data transmitted on each TrCH (the number of blocks N _BLK And block bit length L _BLK ) Is uniquely determined by a combination of transport formats that specify
[0009]
The transport format is numbered and described as TFI (Transport Format Indicator). For example, FIG. 14A shows an example of a TFI table in a case where a downlink 384 kbps packet standardized by 3GPP is multiplexed on the transport channel TrCH # 2 and DCCH data for the control channel is transmitted on the transport channel TrCH # 2. ) And (B). There are six types of 384 kbps (TrCH # 1) transport formats, and the bit length per TTI is 0 × 336 bits, 1 × 336 bits, 2 × 336 bits, 4 × 336 bits, 8 × 336 bits, and 12 bits. × 336 bits, and the TFI is 0, 1, 2, 3, 4, 5. Further, there are two types of transport formats of DCCH data (TrCH # 2) for the control CH, the bit length per TTI is 0 × 148 bits, 1 × 148 bits, and TFI is 0 and 1, respectively.
[0010]
If there are only two types of transport channels, TrCH # 1 and TrCH # 2, there are a total of 12 TFI combinations of TrCH # 1 and TrCH # 2 as shown in FIG. On the other hand, the TFCI is determined, and the transmitting side determines the TFCI according to the combination, encodes the TFCI, and transmits the encoded TFCI. For example, data of 2 × 336 bits per TTI and data of 1 × 336 bits per TTI are continuously transmitted from TrCH # 1 of TTI = 20 msec and the number of bits per TTI from TrCH # 2 of TTI = 40 msec. If 1 × 148-bit data is transmitted, the multiplexed data for 4 frames every 10 ms is a combination of TFIs as shown in FIG. Therefore, the TFCI in each combination is subjected to an encoding process to create a TFCI Code Word (32-bit data), and the TFCI Code Word is transmitted for each frame. On the receiving side, the TFCI Code Word is decoded to determine the TFCI, the transport format (TFI) of each TrCH is determined from the TFCI, and the number of blocks per TTI N for each TrCH is determined from the TFI table. _BLK , Block bit length L _BLK And the bit length of the TTI is determined to perform decoding processing.
The TFCI Code Word is obtained, for example, by converting a TFCI value into a codeword constituting one row of a Hadamard matrix. Further, the compound processing of TFCI is performed by performing a Hadamard transform (Fast Hardmard Transform) on the received code. That is, the TFCI decoder calculates the likelihood for all the allowed TFCIs using Fast Hardarm Transform, and determines the TFCI with the highest likelihood as the transmitted TFCI. Since the decoding operation of the TFCI is well known, a detailed description is omitted.
[0011]
(C) Operation during random access
By the way, in the access state (Access State), data to be received by the mobile station MS occurs instantaneously, and this time is about several tens of ms. However, the receiving device of the mobile station MS is in a standby state continuously because the section for receiving data is unknown, that is, when it is unknown when to receive data, and always demodulates and decodes data. I have. For this reason, there is a problem that even when data is not received, the current consumption increases because each unit performs the receiving operation, and the battery is greatly consumed.
As a conventional technique for reducing battery consumption, in a power saving system of a W-CDMA terminal in which radio waves are transmitted from a plurality of base stations during standby, a search is made for a reception base station having the best reception level among a plurality of base stations, There is a technology (Patent Document 1) for reducing the current consumption of a battery during standby by receiving from only the receiving base station.
Further, as a conventional technique for improving the TFCI determination accuracy and reducing the processing amount and current consumption for the TFCI determination, there is a technique for certifying a TFCI having a maximum value equal to or greater than a threshold as a reception data format (Patent Document 2). .
[Patent Document 1] JP-A-2001-169337
[Patent Document 2] JP-A-2002-164871
[0012]
[Problems to be solved by the invention]
The above prior art does not prevent an increase in current consumption due to demodulation and decoding of data continuously and continuously in an access state (Access State), but always continuously executes data in an access state (Access State). Demodulation and decoding are performed.
Accordingly, an object of the present invention is to reduce the current consumption of the battery by stopping the operation of the data decoding unit by predicting a period in which there is no possibility of receiving data.
Another object of the present invention is to predict a period in which there is no possibility of receiving data and stop the operation of not only the data decoding unit but also other despreading units, demodulation units, searchers, reception units, and the like to reduce the battery power consumption. It is to reduce current consumption.
[0013]
[Means for Solving the Problems]
In the first embodiment of the present invention, the quality of a signal reception state from a base station is determined, and a likelihood value obtained in a decoding process of TFCI included in a downlink common channel (for example, SCCPCH) received from the base station is determined. It is determined whether is smaller than the threshold, the reception state is good, when the likelihood value is smaller than the threshold, the operation of the decoding unit of the mobile station is stopped, when the reception state is good and the likelihood value is larger than the threshold, When the reception state is bad, the decoding unit operates. According to the first embodiment, the operation of the data decoding unit can be turned on / off by predicting whether or not there is a possibility of receiving data, and the current consumption of the battery can be reduced.
[0014]
In the second embodiment, the following control is performed in addition to the control of the first embodiment. When the maximum TTI of the transport channel TrCH in the downlink common channel (SCCPCH) is composed of a plurality of frames, the determination is performed in a specific frame among the plurality of frames, the reception state is good, and the likelihood value is smaller than a threshold. When it is smaller, the despreading process and the demodulation process of the downlink common channel SCCPCH are stopped in a frame period other than the specific frame of the maximum TTI. According to the second embodiment, not only the data decoding unit but also the operations of the despreading unit and the demodulation unit of the downlink common channel are turned on / off by predicting whether there is a possibility of receiving data and consumed. The current can be reduced.
[0015]
In the third embodiment, the following control is performed in addition to the control of the first embodiment. When the maximum TTI of the transport channel TrCH in the downlink common channel (SCCPCH) is composed of a plurality of frames, the determination is performed in a specific frame among the plurality of frames, the reception state is good, and the likelihood value is smaller than a threshold. When it is smaller, the despreading process and the demodulation process of the downlink common channel SCCPCH and the common pilot channel CPICH for S determination and the path search process and the reception process are stopped in a frame period other than the specific frame of the maximum TTI. According to the third embodiment, the current consumption can be further reduced, and even when such control is performed, the S determination can be periodically performed.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
(A) First embodiment
FIG. 1 is a configuration diagram of a first embodiment of a mobile station in a random access state.
The first embodiment of FIG. 1 is different from the prior art of FIG. 11 in that (1) a non-reception determining unit 11 is added, and (2) the TFCI decoder 7 inputs the TFCI likelihood to the no-reception determining unit 11. (3) The S determination unit determines whether the reception state is good or not, and inputs the result to the no reception determination unit 11. (4) The no reception determination unit 11 is based on the TFCI likelihood and the reception state. That is, ON / OFF of the decoding process of the decoding unit 8 is controlled. The S determining unit 10 determines whether the reception state is good or not based on whether the pilot signal level or the despread result (Ec / No (dB) of CPICH) of the despreading unit 4 is equal to or greater than a threshold. The failure is input to the no reception determination section 11. Also, the TFCI decoder 7 may compare the TFCI likelihood with a threshold value and input the magnitude determination result to the no-reception determination unit 11.
The no-reception determining unit 11 uses the S determination result and the likelihood of the TFCI to identify a section in which no received data exists (a section in which no data is received), and stops the decoding process in the section.
[0017]
The downlink common channel SCCPCH may not be transmitted by the base station BTS in a section where no data exists. Therefore, in this case, the likelihood of the TFCI also decreases. However, it is assumed that the likelihood of TFCI is reduced by interference or the like. Therefore, referring to the S determination result, when the S determination result is good, the reception state is good, interference is small, and the section with data and the section without data can be determined based on the likelihood of TFCI. That is, when the S determination result is good, (1) if the likelihood of the TFCI is large, it can be determined that the section has received data. If (2) the likelihood of the TFCI is small, it is determined that the section has no received data. Judgment can be made and bipolarization can be performed.
[0018]
FIG. 2 shows the relationship between the probability distribution A without data and the probability distribution B with data when the S determination result is defective. When the S determination result is bad, the probability of no data increases if the TFCI likelihood is small, and the probability of data presence increases if the TFCI likelihood is large. However, when the S determination result is bad, the probability distribution A without data and the probability distribution B with data intersect. For this reason, it is impossible to reliably predict the absence of data and the presence of data based on the TFCI likelihood in the intersection section. On the other hand, when the S determination result is good, the probability distribution A with no data and the probability distribution B with data do not intersect.
[0019]
FIG. 3 shows the relationship between the probability distribution A with no data and the probability distribution B with data when the S determination result is good. When the S determination result is good, if the TFCI likelihood is small, the probability of no data increases, and if the TFCI likelihood is large, the probability of data presence increases, but the probability distribution A of no data and the probability distribution B of data presence intersect. do not do. For this reason, the absence-of-reception determining unit 11 determines the likelihood of the TFCI and the threshold TFCI set in advance. _TH To determine the level of the TFCI likelihood, and refer to the S determination result to accurately specify the no-reception section. That is, the absence-of-reception determining unit 11
{Circle around (1)} When the S determination result is good, that is, when the reception state is good, the TFCI likelihood is equal to the threshold TFCI. _TH If it is smaller, it is determined to be a data-less section,
(2) When the S determination result is good, that is, when the reception state is good, the TFCI likelihood is equal to the threshold TFCI. _TH If it is larger, it is determined to be a section with data,
{Circle around (3)} When the S determination result is bad, that is, when the reception state is bad, it is determined that the section without data and the section with data cannot be distinguished.
[0020]
FIG. 4 is a diagram for explaining the operation of the first embodiment. The no-reception determining unit 11 determines whether the state is the above (1) to (3). If the state is (1), the operation of the decoding unit 8 is determined. The power is turned off (the power of the decoding unit is turned off), and in the cases of (2) and (3), the operation of the decoding unit 8 is turned on (the power of the decoding unit is turned on).
FIG. 5 is an example of a series of reception processing during random access reception, a reception section absence determination, and a control flow example of the decoding unit.
It is monitored whether the S determination timing has come (step 101). If the S determination timing, the despreading unit 4 and the demodulation unit 6 demodulate the pilot signal by despreading the common pilot channel CPICH (step 102). 7 makes an S determination based on the pilot signal level, and inputs the determination result to the no reception determination section 11 (step 103).
The despreading unit 3 and the demodulation unit 5 despread the downlink common channel SCCPCH to demodulate data and TFCI (step 104). The TFCI decoder 7 decodes the TFCI from the TFCI Code Word and inputs the TFCI to the decoding unit 8, and inputs the TFCI likelihood to the no-reception determining unit 11 (step 105).
[0021]
Next, the absence-of-reception determining unit 11 performs the absence-of-reception determination (step 106). In the no-reception determination, the no-reception determination unit 11 refers to the S determination result (step 106a), and if the S determination is poor, that is, if the reception state is poor, the TFCI likelihood may cause interference as shown in FIG. Therefore, control is performed so that the decoding process is continued without performing the reception absence determination based on the threshold value. On the other hand, if the S determination is good, that is, if the reception state is good, as shown in FIG. 3, since the TFCI likelihood is not affected by interference, a TFCI decoding result is obtained (step 106c). Threshold TFCI _TH (Step 106d).
[0022]
TFCI likelihood is threshold TFCI _TH If it is higher, it is determined that there is a reception section, and power supply to the decoding unit 8 is continued to perform the decoding process. However, the TFCI likelihood is equal to the threshold TFCI _TH If it is lower, it is determined that there is no reception section, the power supply to the decoding unit 8 is turned off, the decoding process is stopped, and power saving is realized (step 106e). Thus, when a mobile station (terminal device) is located in an area where the S determination is good, it becomes possible to operate the mobile station decoding process only when the network transmits information.
Thereafter, if there is no data input (step 107), the decoding unit 8 does not perform the decoding operation, and if there is a data input, executes the decoding operation and inputs the decoding result to the upper layer unit 9 (step 108).
[0023]
(B) Second embodiment
FIG. 6 is a configuration diagram of a second embodiment of the mobile station in the random access state.
The second embodiment of FIG. 6 is different from the first embodiment of FIG. 1 in that (1) the determination process of the no-reception determination unit 11 and (2) the despreading process of the common channel SCCPCH by going down the range in which the operation is stopped. This is an extension to demodulation processing.
In the specific frame of the maximum TTI in the downlink common channel SCCPCH, the same non-reception determination as in the first embodiment is performed, and if the specific frame (for example, the first frame) is a non-reception section, the corresponding TTI is subsequently determined. The decoding process is stopped, and despreading and demodulation of the SCCPCH are stopped in frames other than the specific frame in the corresponding TTI. This is because the 3GPP defines that the same TFCI is used in the maximum TTI of the TrCH in the downlink common channel SCCPCH. Therefore, if a specific frame in the maximum TTI has no data, the TTI interval is All can be regarded as no data. Therefore, despreading and demodulation processing are performed on a specific frame (for example, the first frame) to extract the likelihood of TFCI, and as a result, if it is determined that there is no data, despreading and demodulation are performed on other frames within the same TTI. Can be unnecessary.
[0024]
As described above, when the maximum TTI of the transport channel TrCH in the downlink common channel SCCPCH is composed of a plurality of frames, the no-reception determining unit 11 performs the same determination as in the first embodiment in the first frame of the plurality of frames. Do. [1] When the reception state is good and the likelihood value is smaller than the threshold, the power of the decoding unit 8 after (1) is turned off to stop the operation, and (2) other than the top frame of the maximum TTI. The despreading process and the demodulation process of the downlink common channel SCCPCH are stopped in the frame period.
On the other hand, when [2] the reception state is good and the likelihood value is larger than the threshold value, (3) the decoding process is continued without stopping, and (4) the SCCPCH despreading process and the demodulation process are also continued.
[3] When the S determination result is bad, that is, when the reception state is bad, it is determined that the data-free section and the data-present section cannot be distinguished, and (5) the decoding process is continued without stopping, and (6) SCCPCH. The despreading process and the demodulation process are also continued.
[0025]
FIG. 7 is an explanatory diagram of the operation of the second embodiment when the maximum TTI is 2 frames. The no-reception determining unit 11 determines whether the first frame of the maximum TTI is always in the state of [1] to [3]. I do. Then, in the state of [1], (1) the operation of the decoding unit 8 is turned off (the power of the decoding unit is turned off), and (2) the despreading unit 3 and the demodulation unit 5 in frame periods other than the first frame. Off (power off). In the state of [2], (3) the operation of the decoding unit 8 is turned on (the power of the decoding unit is turned on), and (4) the operations of the despreading unit 3 and the demodulation unit 5 are turned on. In the state of [3], (5) the operation of the decoding unit 8 is turned on (the power of the decoding unit is turned on), and (6) the operations of the despreading unit 3 and the demodulation unit 5 are turned on.
[0026]
FIG. 8 shows an example of a control flow of a series of reception processing during reception of random access, determination of absence of a reception section, a decoding unit, and the like. The same parts as those in the flow of the first embodiment of FIG.
The difference is that after the processing in steps 101 to 103, it is checked whether the frame is a specific frame (leading frame) having the maximum TTI (step 201), and if it is the leading frame, the same processing in steps 104 to 108 as in the first embodiment is performed. I do. However, if it is determined in step 106 that the section is a non-reception section, the power supply to the decoding unit 8 is turned off to stop the decoding process, power saving is realized, and a frame section other than the first frame of the TTI, The power supply to the spreading unit 3 and the demodulation unit 5 is turned off to stop the despreading process and the demodulation process, thereby realizing power saving.
[0027]
In step 201, if it is not the first frame, it is determined whether or not there is reception (step 202). If there is no reception, despreading, demodulation and decoding are not performed. On the other hand, if there is reception, despreading processing, demodulation processing, and decoding processing are being performed, so that these processings are performed and the decoded data is input to the upper layer unit 9 (step 203￣205).
According to the second embodiment, the non-reception determination is performed only for a specific frame, thereby stopping the SCCPCH despreading process, demodulation process, and decoding process for all TTI frames other than the specific frame of the TTI determined to be non-reception. Power can be saved.
[0028]
(C) Third embodiment
FIG. 9 is a configuration diagram of a third embodiment of the mobile station in the random access state.
The third embodiment of FIG. 9 differs from the second embodiment of FIG. 6 in that when the no-reception determining unit 11 determines that there is no reception in a specific frame section of the maximum TTI, the decoding unit 8 and the despreading unit for SCCPCH are used. 3. The operation of the demodulation unit 5 is stopped, and the operations of the radio reception unit 1, the searcher 2, the despreading unit 4 for the common pilot channel CPICH used for S determination, and the demodulation unit 6 are also stopped.
The S determination need not be performed continuously, but may be performed periodically. Therefore, the despreading and demodulation operations of the CPICH are performed in a specific frame (for example, the first frame) of the second embodiment. CPICH despreading and demodulation can also be stopped. That is, when the absence-of-reception determining unit 11 determines that there is no reception in the specific frame section of the maximum TTI, (1) the operation of the decoding unit 8 is turned off (the power of the decoding unit is turned off), and (2) the specific frame of the maximum TTI. In the other frame periods, the despreading process and the demodulation process of the downlink common channel SCCPCH and the common pilot channel CPICH are stopped, and the path search process and the reception process are stopped.
[0029]
FIG. 10 shows an example of a control flow of a series of reception processing during reception of random access, determination of absence of a reception section and a decoding unit, and the same parts as those in the flow of the first embodiment of FIG.
The difference is that it is first determined whether or not the current frame is a specific frame (leading frame) having the maximum TTI (step 301). Is a point. However, if it is determined in step 106 that the section is a non-reception section, the power supply to the decoding unit 8 is turned off to stop the decoding process, power saving is realized, and a frame section other than the first frame of the TTI, The power supply to the spreading units 3, 4, the demodulation units 5, 6, and the searcher 2 is turned off to stop the despreading process, the demodulation process, and the search process, thereby realizing power saving.
[0030]
In step 301, if the frame is not the first frame, it is determined whether or not there is reception (step 302). If there is no reception, the power supply to the wireless reception unit 1 is turned off to stop the reception process, thereby realizing power saving (step 303). ).
On the other hand, if there is a reception in step 302, it is determined that the reception frame exists in the first frame, and the radio reception unit 1, searcher 2, despreading units 3, 4, demodulation units 5, 6, and decoding unit 8 are operating. , The despreading unit 3 and the demodulation unit 5 perform a despreading process and a demodulation process, and the decoding unit 8 performs a decoding process using the TFCI and inputs the decoded data to the upper layer unit 9 (steps 304 to 306).
According to the third embodiment, by performing the S determination process on the specific frame for which the no-reception determination is performed, all the reception systems and the maximum TTI within the frame section other than the specific frame of the maximum TTI determined to have no reception are performed. Power saving can be realized by stopping demodulation and decoding of all frames.
[0031]
【The invention's effect】
According to the present invention as described above, it is determined whether the signal reception state from the base station is good or not, and whether the likelihood value obtained in the decoding process of the TFCI included in the downlink common channel received from the base station is smaller than the threshold, When the reception state is good and the likelihood value is smaller than the threshold, the operation of the decoding unit of the mobile station is stopped, so that the current consumption of the battery can be reduced.
Further, according to the present invention, when the maximum TTI of the transport channel TrCH in the downlink common channel is composed of a plurality of frames, the above determination is performed in a specific frame of the plurality of frames, and the reception state is good. When the likelihood value is smaller than the threshold value, the despreading process and the demodulation process of the downlink common channel SCCPCH are stopped in a frame period other than the specific frame of the maximum TTI, so that current consumption can be further reduced. .
Further, according to the present invention, when the maximum TTI of the transport channel TrCH in the downlink common channel SCCPCH is composed of a plurality of frames, the above determination is made in a specific frame of the plurality of frames, and the reception state is good. When the likelihood value is smaller than the threshold value, the despreading process and the demodulation process of the downlink common channel SCCPCH and the common pilot channel CPICH for S determination are stopped and the path search process in a frame period other than the specific frame of the maximum TTI. Since the reception process is stopped, the current consumption can be further reduced, and even when such control is performed, the S determination can be periodically performed.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a first embodiment of a mobile station in a random access state.
FIG. 2 is a relationship diagram between a probability distribution A with no data and a probability distribution B with data when the S determination result is defective.
FIG. 3 is a relationship diagram between a probability distribution A with no data and a probability distribution B with data when the S determination result is good.
FIG. 4 is an operation explanatory diagram of the first embodiment.
FIG. 5 is an example of a series of reception processing during random access reception, a reception section absence determination, and a control flow of a decoding unit.
FIG. 6 is a configuration diagram of a second embodiment of the mobile station in a random access state.
FIG. 7 is an operation explanatory diagram of the second embodiment when the maximum TTI is 2 frames.
FIG. 8 is an example of a control flow of a series of reception processing, a reception section absence determination, a decoding unit, and the like in the second embodiment during random access reception.
FIG. 9 is a configuration diagram of a third embodiment of the mobile station in a random access state.
FIG. 10 is a control flow example of a series of reception processing, reception section absence determination, a decoding unit, and the like in the third embodiment during random access reception.
FIG. 11 is a configuration diagram during random access of a mobile station in a W-CDMA system according to the 3GPP standard.
FIG. 12 is a diagram illustrating the configuration of an SCCPCH frame.
FIG. 13 is an explanatory diagram of a TTI.
FIG. 14 is an explanatory diagram of TFCI.
[Explanation of symbols]
1 Radio section
2 Searcher
3 Despreading section for downlink common channel SCCPCH
4 Despreading unit for common pilot channel CPICH
5, 6 demodulation unit
7 TFCI decoder
8 Decoding unit
9 Upper layer
10 S determination unit
11 Reception non-determination section

Claims (5)

In a random access receiving method of a mobile station in a random access state performing communication between a base station and a mobile station by a downlink common channel and an uplink common channel,
Determination of the quality of the signal reception state from the base station,
Determine whether the likelihood value obtained in the decoding process of the TFCI included in the downlink common channel received from the base station is smaller than a threshold,
When the reception state is good and the likelihood value is smaller than the threshold, the operation of the decoding unit of the mobile station is stopped,
When the reception state is good and the likelihood value is larger than the threshold, and when the reception state is bad, the decoding unit operates.
A random access receiving method characterized by the above-mentioned. When the maximum TTI of the transport channel TrCH in the downlink common channel includes a plurality of frames, the determination is performed in a specific frame of the plurality of frames,
When the reception state is good and the likelihood value is smaller than the threshold, the despreading process and the demodulation process of the downlink common channel are stopped in a frame period other than the specific frame of the maximum TTI.
2. The random access receiving method according to claim 1, wherein: When the maximum TTI of the transport channel TrCH in the downlink common channel includes a plurality of frames, the determination is performed in a specific frame of the plurality of frames,
When the reception state is good and the likelihood value is smaller than the threshold value, the despreading process and the demodulation process of the downlink common channel and the common pilot channel are stopped and the path search process in a frame period other than the specific frame of the maximum TTI. , Stop receiving,
2. The random access receiving method according to claim 1, wherein: In the mobile station random access receiving device performing communication between the base station and the mobile station by downlink common channel and uplink common channel,
A wireless receiving unit that receives a wireless signal,
A first despreading and demodulating unit that despreads and demodulates the data and the TFCI code transmitted on the downlink common channel,
A decoding unit for decoding the demodulated data;
A determining unit that determines whether a likelihood value obtained by decoding the demodulated TFCI is smaller than a threshold,
A second despreading and demodulation unit that despreads and demodulates the signal transmitted on the common pilot channel,
A reception state quality determination unit that determines the quality of the reception state based on the despreading result or demodulation result of the second despreading,
When the reception condition of the downlink signal from the base station is good and the likelihood value obtained in the decoding process of the TFCI included in the downlink common channel received from the base station is smaller than a threshold, the operation of the decoding unit is stopped, When the reception state is good and the likelihood value is larger than the threshold, and when the reception state is bad, the control unit that operates the decoding unit,
A random access receiver for a mobile station, comprising: When the maximum TTI of the transport channel TrCH in the downlink common channel is composed of a plurality of frames, the determination unit performs the determination in a specific frame of the plurality of frames,
When the reception state is good and the likelihood value is smaller than the threshold, the control unit stops the despreading process and the demodulation process of the downlink common channel in a frame period other than the specific frame of the maximum TTI.
The mobile station random access receiving apparatus according to claim 4, wherein:

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