JP2007027917A - Receiver, communication terminal and receiving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce power consumption by stopping processing when a signal of a predetermined modulation system is received. <P>SOLUTION: A wireless receiving section 102 receives a signal for GSM and outputs a baseband signal from the received signal. A demodulating section 104 performs GMSK demodulation of the baseband signal. A demodulating section 105 demodulates the baseband signal subjected to GMSK demodulation and outputs reception data. A modulation system detecting section 106 detects a predetermined modulation system from the baseband signal. Based on the detection results from the modulation system detecting section 106, a signal processing control section 107 stops operation of at least one of the wireless receiving section 102, the modulation system detecting section 106 and a received signal processing section 103 for a predetermined time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a receiving apparatus, a communication terminal apparatus, and a receiving method, and in particular, a receiving apparatus and communication that are mounted on a mobile radio terminal apparatus and operate on a packet data communication system in which a plurality of users share the same physical channel. The present invention relates to a terminal device and a receiving method.

  Since the packet communication method shares a single line among a plurality of users, the line use efficiency can be improved, and is currently widely used in fields such as the Internet. Also in the field of mobile communication, for example, GPRS (General Packet Radio Service) designed based on GSM (Global System for Mobile communications) adopts a packet communication system and uses physical channels (radio frequency, time slot). Can be shared by a plurality of mobile radio terminals to perform data communication. In recent years, EGPRS (Enhanced GPRS), which is an extension of the GPRS system, has been introduced, and higher-speed packet data communication can be performed.

  FIG. 5 is a diagram illustrating a GPRS multiframe configuration. One unit of GPRS communication period is called one multiframe. One multi-frame 500 is composed of 52 frames 501, and one frame is further composed of eight time slots 502. In GPRS, one or more time slots can be assigned to a user.

  Of these 52 frames, the number of frames that can be assigned to a logical channel PDTCH (Packet Data Traffic CHannel) used in packet communication is 48. The 48 frames are 12 in total by radio blocks composed of 4 consecutive frames. Are divided into wireless blocks B0 to B11. The GPRS network allocates resources to users in units of this radio block.

  As shown in CS1 to CS4 in FIG. 6, four types of CS (Coding Scheme) are defined for the PDTCH transmission rate depending on the coding rate, and the GPRS network determines which CS to use. It is determined according to the transmission state of the user.

  The EGPRS multi-frame configuration is exactly the same as GPRS. A major difference from GPRS is that nine types of MCS (Modulation and Coding Scheme) are defined depending on the difference in modulation scheme and coding rate, as indicated by MCS1 to MCS9 in FIG.

  In GPRS or EGPRS, a physical channel is shared by a plurality of users in units of radio blocks. In addition, the GPRS user and the EGPRS user may share the same physical channel (for example, Non-Patent Document 1).

  Since which GPRS network determines which user is assigned to which radio block, the mobile radio terminal device must always receive all radio blocks in the downlink channel. However, a signal that is actually necessary for one user is a part of the radio blocks, and particularly in a situation where a line is crowded among a plurality of users, most of the radio blocks are unnecessary signals. For a mobile radio terminal device, such an operation is useless from the viewpoint of power consumption, and it is important to refrain from receiving unnecessary signals as much as possible in order to increase the packet communication possible time.

Conventionally, as a method for reducing power consumption of a mobile radio terminal device during packet communication, a method of detecting a non-transmission section of a GPRS network and placing the mobile radio terminal device in a power saving mode within the radio block period is known (For example, patent document 1).
JP 2003-179534 A 3GPP TS04.60 V8.25.0 (2004-09), Section 5.2.4a, page 20

  However, the method of reducing power consumption described in Patent Document 1 can save power only in a non-transmission period. For example, in a congested situation where many users share the same physical channel, there is no power saving. There is a problem that the frequency of the transmission interval is very small and a large power saving effect cannot be obtained.

  The present invention has been made in view of the above points, and a receiving apparatus, a communication terminal apparatus, and a receiving method that can reduce power consumption by stopping processing when a signal of a predetermined modulation scheme is received. The purpose is to provide.

  The receiving apparatus according to the present invention is a radio receiving unit configured to receive a signal of a different communication method in the block unit including a plurality of blocks and the block including a plurality of frames, and obtain a baseband signal from the received signal And a modulation scheme detection unit that detects a modulation scheme of a received signal from the baseband signal obtained by the wireless reception unit, and a modulation scheme detected by the modulation scheme detection unit is not used in a communication scheme in communication In the case of the modulation scheme, a configuration is adopted that includes signal processing control means for stopping the processing of the signal of the received frame after the frame in which the modulation scheme in the block is detected.

  The receiving method of the present invention includes a step of receiving a signal of a different communication method in the block unit configured of a plurality of blocks and the block including a plurality of frames, and obtaining a baseband signal from the received signal; Detecting a modulation method of a received signal from the obtained baseband signal, and detecting the modulation method in the block when the detected modulation method is a modulation method not used in a communication method in communication And a step of stopping the processing of the signal of the received frame after the completed frame.

  According to the present invention, power consumption can be reduced by stopping processing when a signal of a predetermined modulation method is received.

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

(Embodiment)
FIG. 1 is a block diagram showing a configuration of receiving apparatus 100 according to the embodiment of the present invention. First, the configuration of the receiving apparatus 100 of the present invention will be described with reference to FIG.

  101 is an antenna, 102 is a radio reception unit that receives a GSM signal and outputs a baseband signal from the received signal, 103 is a demodulation unit 104 that demodulates the baseband signal, and a decoding unit 105 that performs decoding processing. The received signal processing unit 106 includes: a modulation scheme detection unit 106 that detects a predetermined modulation scheme from the baseband signal; 107, based on the detection result of the modulation scheme detection unit 106, the wireless reception unit 102, the modulation scheme; It is a signal processing control unit that controls at least one operation of the detection unit 106 and the reception signal processing unit 103 to stop for a predetermined time.

  In the receiving apparatus 100 configured as described above, a signal transmitted from a base station (not shown) is received by the antenna 101, converted into a baseband signal by the wireless receiving unit 102, and received signal processing is performed by the received signal processing unit 103. Is called. In the reception signal processing unit 103, the demodulation unit 104 performs GMSK demodulation using the baseband signal obtained from the wireless reception unit 102, and the decoding unit 105 performs decoding processing. On the other hand, the baseband signal obtained from the wireless reception unit 102 is also input to the modulation scheme detection unit 106, detects the modulation scheme of the received signal, and determines the modulation scheme. The determination result is input to the signal processing control unit 107, and the signal processing control unit 107 performs on / off control of the operations of the wireless reception unit 102, the received signal processing unit 103, and the modulation scheme determination unit 106 according to the determination result.

  Next, a specific operation of receiving apparatus 100 according to the present embodiment will be described in detail with reference to FIG. 2 and FIG. 3, taking a receiving apparatus performing packet communication with GPRS as an example.

  FIG. 2 is a diagram illustrating an example of downlink PDTCH allocation in GPRS, and FIG. 3 is a flowchart illustrating the operation of the reception apparatus 100.

  Here, the receiving apparatus 100 performs packet communication in the GPRS mode using the frame of User1 in FIG. On the other hand, it is assumed that User2 is another user and performs packet communication in the EGPRS mode. In the case of GPRS and EGPRS packet communication, multi-slot communication using a plurality of time slots is also possible, but in this embodiment, the number of assigned time slots is set to 1 for the sake of simplification.

  First, receiving apparatus 100 receives burst data of the first frame of the radio block (ST301). This received signal is converted into a baseband signal by radio receiving section 102, then the modulation scheme is detected by modulation scheme detector 106, and the detected modulation scheme is determined (ST302).

  If the modulation scheme detection unit 106 determines that the received signal is not an 8PSK modulation signal (No in ST303), there is a possibility of packet data addressed to itself, so the demodulation unit 104 of the received signal processing unit 103 GMSK demodulation is performed (ST304). Thereafter, burst data reception of the second frame (ST305) and its demodulation processing (ST306), burst data reception of the third frame (ST307) and its demodulation processing (ST308), burst data reception of the fourth frame (ST309) and its Demodulation processing (ST310) is performed, and decoding processing is performed using the demodulation results of the last received four burst data (ST311).

  On the other hand, when the modulation scheme detection unit 106 determines that the received signal is an 8PSK modulated signal (Yes in ST303), since it can be determined that the packet data is not addressed to itself, a reception error is notified (ST312), The reception processing operation is suspended until the next radio block time (ST313). The above process is repeated for each radio block.

  Specifically, in the case of FIG. 2, when an 8PSK modulation signal is received in the first frame 201 of the continuous four frames 201 to 204 constituting the radio block, the receiving operation of the remaining three frames 202 to 204 is suspended. To do. In the configuration of FIG. 1, it is possible to pause the operations of the wireless reception unit 102, the reception signal processing unit 103, and the modulation scheme detection unit 106, and only one frame out of four frames needs to be operated. Power consumption can be reduced.

  Further, in this case, it is not necessary to perform demodulated signal processing even in the first one frame. For example, arithmetic processing in an arithmetic processing device such as a DSP can be suspended, and further power consumption reduction can be realized.

  For example, the modulation scheme detection unit 106 can detect and determine the modulation scheme by focusing on the phase component of the received baseband signal. FIG. 4 is a diagram illustrating mapping of symbol points of GMSK modulation used in GSM, GPRS, and the like and 3π / 8 shift 8PSK modulation used in EGPRS. As shown in FIG. 4, the amount of phase rotation between adjacent received symbols in GMSK modulation is ± π / 2. On the other hand, in 3π / 8 shift 8PSK modulation, the amount of phase rotation is any one of ± π / 8, ± 3π / 8, ± 5π / 8, ± 7π / 8, and therefore the amount of phase rotation differs from that of the GMSK modulation signal. . Therefore, if the phase rotation amount of the symbol in the received burst is calculated, the modulation method can be determined easily and accurately. Furthermore, if a known sequence portion located at the center of each burst is used, the phase rotation amount does not depend on the symbol data, so that the detection accuracy can be further improved.

  Further, the modulation method detection / detection in the modulation method detection unit 106 measures the quality of the received signal, compares the measured received signal quality with a preset threshold value, and only when the received signal quality is higher than the threshold value. If the determination of the modulation method is performed, the determination accuracy can be improved.

  As described above, according to the present embodiment, for example, in a situation where a GPRS user and an EGPRS user share the same physical channel, in the first frame of the continuous four frames constituting the radio block, the GPRS user When it is detected that the packet data for the modulated EGPRS user is received, the reception operation is stopped for the remaining three frames, so that power consumption can be reduced.

  The present embodiment can also be applied to the case where the interference wave power is measured in a plurality of time slots. For example, when the number of time slots to be measured is 4, in FIG. 3, burst signals for 4 time slots are received, the modulation signal in each time slot is determined, and reception is performed in units of time slots according to each determination result. It can be realized if it operates. In this embodiment, at least one of the operations of the wireless reception unit 102, the demodulation unit 104, and the decoding unit 105 is stopped. However, the present invention is not limited to this, and the wireless reception unit 102, the demodulation unit 104, and the decoding unit The operation of processing signals other than the unit 105 can be stopped. Moreover, the receiving apparatus 100 of this Embodiment is applicable to the communication terminal device which communicates with a base station.

  The receiving apparatus, communication terminal apparatus and receiving method according to the present invention are particularly suitable for a mobile radio terminal apparatus for GSM.

The block diagram which shows the structure of the receiver which concerns on embodiment of this invention The figure which shows an example of allocation of downlink PDTCH in GPRS used for the receiver which concerns on embodiment of this invention Flow chart for explaining the operation of the receiving apparatus according to the embodiment of the present invention The figure which shows the mapping of the symbol point of GMSK modulation and 3 (pi) / 8 shift 8PSK modulation which concerns on embodiment of this invention Schematic diagram of GPRS multi-frame configuration Diagram showing CS defined by GPRS and MCS defined by EGPRS

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Receiver 101 Antenna 102 Radio | wireless receiving part 103 Reception signal processing part 104 Demodulation part 105 Decoding part 106 Modulation system detection part 107 Signal processing control part

Claims (6)

Radio receiving means configured to receive a signal of a different communication method in units of the block configured of a plurality of blocks and the block configured of a plurality of frames, and to obtain a baseband signal from the received signal;
A modulation scheme detection unit that detects a modulation scheme of a received signal from the baseband signal obtained by the wireless reception unit;
If the modulation method detected by the modulation method detection means is a modulation method that is not used in the communication method during communication, processing of the signal of the frame received after the frame in which the modulation method is detected in the block is stopped. Signal processing control means,
A receiving apparatus comprising: Demodulation means for demodulating the baseband signal obtained by the wireless reception means;
Decoding means for decoding the baseband signal demodulated by the demodulation means,
The receiving apparatus according to claim 1, wherein the signal processing unit stops at least one of the processing of the wireless reception unit, the processing of the demodulation unit, and the processing of the decoding unit.   The receiving apparatus according to claim 1, wherein the modulation scheme detection unit detects the modulation scheme by calculating a phase rotation amount of adjacent symbols of the reception signal.   The modulation scheme detection means measures the signal quality of the received signal and stops processing of a frame received after the frame in which the modulation scheme in the block is detected when the measured signal quality is higher than a threshold value. The receiving device according to any one of claims 1 to 3.   A communication terminal device comprising the receiving device according to claim 1. Receiving a signal of a different communication method in the block unit composed of a plurality of blocks and the block being composed of a plurality of frames, and obtaining a baseband signal from the received signals;
Detecting a modulation method of a received signal from the obtained baseband signal;
When the detected modulation scheme is a modulation scheme that is not used in the communication scheme in communication, stopping processing of a signal of a frame received after the frame in which the modulation scheme in the block is detected;
A receiving method comprising:

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