JP3828120B2 - Mobile radio communication system, receiver, transmitter, and mobile radio communication method - Google Patents

Description

  The present invention relates to a mobile radio communication system in which a UMTS and a GSM system coexist, a receiver, a transmitter and a mobile radio communication method applied to the mobile radio communication system, and in particular, a mobile radio communication system. The present invention relates to a technique for observing a control channel of a GSM system, which is another system, using idle time.

  In the CDMA cellular system, since the same carrier frequency is repeatedly used in any cell, there is no need for inter-frequency handover in the same system. However, considering the coexistence with existing systems, handover between different carrier frequencies is required. Three specific cases are listed below.

  The first point is a case where another carrier frequency is used to increase the number of subscribers in a cell with a lot of traffic, and a handover is performed between the cells. The second point is a case where different carrier frequencies are assigned to large and small cells in the umbrella cell configuration, and handover is performed between the cells. The third point is a case where a handover is performed between a third generation system such as a broadband mobile radio communication system and a second generation system such as an existing mobile phone system.

  In such a case, handover is performed, and in this case, it is necessary to detect the power of carriers of different frequencies. In order to realize this detection, it is sufficient that the receiver has a structure capable of detecting two frequencies, but this increases the configuration of the receiver or makes the configuration complicated.

In addition, as a handover method, a mobile-initiated handover (Mobile
Two types are considered: Assisted Handover (MAHO) and network-led handover (Network Assisted Handover: NAHO). When MAHO and NAHO are compared, NAHO places a smaller burden on the mobile device, but this requires synchronization between the mobile device and the base station. In addition, the base station / network configuration is complicated and large so that each mobile device can be tracked.

  For this reason, the realization of MAHO is desired, but it is necessary to observe the strengths of two different frequency carriers in the mobile station in order to determine whether or not to perform handover. However, unlike the time division multiple access (TDMA) system used in the second generation, the CDMA cellular system normally uses a continuous transmission form for both transmission and reception. In this continuous transmission technique, unless a receiving device having two frequencies is prepared, it is necessary to stop transmission or reception timing and observe other frequencies.

  To date, a technology related to compressed mode (Compressed Mode) has been proposed, in which transmission information in the normal mode is time-compressed and transmitted in a short time, and other frequency carriers are observed with other time margins. Yes. As an example, there is “discontinuous transmission for seamless handover in DS-mobile radio communication system” described in Patent Document 1. This document discloses a technique for realizing a compressed mode in which the transmission time is shortened by lowering the spreading factor of the spreading code to be used.

  Here, a method for realizing the compressed mode according to the above-described literature will be described. FIG. 13 shows a transmission example in a normal mode and a compressed mode in a conventional mobile radio communication system. In FIG. 13, the vertical axis indicates transmission speed / transmission power, and the horizontal axis indicates time. In the example of FIG. 13, compressed mode transmission is inserted between normal transmission frames. In transmission in this compressed mode, a non-transmission time is provided in the downstream frame, and the time can be arbitrarily set. This non-transmission time refers to an idle time set for measuring the strength of another frequency carrier. In this way, slotted transmission is realized by inserting idle time between compressed mode frame transmissions.

  In such a compressed mode transmission, the transmission power is increased according to the time ratio between the idle time and the frame (compressed mode frame) transmission time, and therefore, as shown in FIG. The compressed mode frame is transmitted with higher transmission power. Thereby, transmission quality can be maintained even in frame transmission in the compressed mode.

Japanese translation of PCT publication No. 8-500475

  Normally, between GSM and GSM, observation of different frequency components (control channel) is performed using one observation time (no transmission time) assigned for each superframe, but UMTS and GSM system coexist. Assuming a mobile radio communication system, an operation for observing the frequency component of the GSM system between different systems, that is, from UMTS, is necessary. Also in this case, similarly to the GSM-GSM observation, a free time for observing the GSM frequency component is set in the UMTS superframe.

  That is, it is necessary to allocate an observation time consisting of the same number of idle slots as in the case of observation between GSM and GSM to one superframe frame in UMTS. Due to this limitation, it is difficult to insert all the observation times in one frame, and a technique for observing the frequency components of the GSM system from UMTS is expected in the future.

  In order to solve the above-described problems caused by the conventional example, the present invention reliably observes the frequency components of other systems from the UMTS even when the UMTS and other systems coexist, and at that time, interleaves compressed mode frames. It is an object of the present invention to obtain a mobile radio communication system capable of suppressing deterioration in performance, a receiver, a transmitter, and a mobile radio communication method applied to the mobile radio communication system.

  In order to solve the above-described problems and achieve the object, the mobile radio communication system according to the present invention transmits a first specific number of frames each having a predetermined number of slots and having a first frame length. A CDMA (Code Division) including a transmitter that transmits the frame in units of the first transmission period, and a receiver that receives a frame transmitted by the transmitter. A first communication system of a multiple access system, and a period required to transmit a second specific number of frames having a second frame length and not an integer multiple of the first transmission period. In a mobile radio communication system in which a second communication system that performs frame transmission using a communication method with a transmission cycle coexists, a transmitter of the first communication system includes a plurality of non-transmission devices within the first transmission cycle. A transmission time is provided, and the interval L is determined in units of the number of slots so that the interval L between the front ends of each non-transmission time is equal to an odd multiple of a value obtained by dividing the second frame length by an even number. A frame in which no-transmission time is arranged at an interval is transmitted to the receiver of the first communication system, and the receiver of the first communication system controls the second communication system during the no-transmission time. It is characterized by observing a data transmission channel.

  According to the present invention, a mobile unit capable of reliably observing the control data transmission channel of the second communication system from the first communication system and suppressing the deterioration of the interleave performance of the compressed mode frame at that time There is an effect that a wireless communication system can be obtained.

  Hereinafter, embodiments of a mobile radio communication system, a receiver, a transmitter, and a mobile radio communication method applied to the mobile radio communication system according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
First, the principle of Embodiment 1 of the present invention will be described. In the first embodiment of the present invention, a mobile radio communication system in which a UMTS and a GSM system coexist is shown as an example. First, the GSM system which is an existing system will be described. FIG. 1 shows a frame format applied to the GSM system. Specifically, FIG. 1A is a diagram illustrating the frame format of the dedicated traffic channel, and FIG. 1B is a diagram illustrating the frame format of the common control channel.

  In the GSM system, TACH (Traffic and Associated Channel) is defined as an individual traffic channel, and FCCH (Frequency Collection Channel) and SCH (Synchronization Channel) are defined as common control channels. In the dedicated traffic channel TACH, as shown in FIG. 1A, a cycle for transmitting frames as transmission units from # 1 to # 26 is set as a 1GSM superframe. One frame is 8 BP (Burst Period) time. 1BP is 0.577 ms. Therefore, a 1 GSM superframe has a transmission period of 120 ms. In the common control channel FCCH / SCH, as shown in FIG. 1 (b), the cycle for transmitting 8BP frames from # 1 to # 51 is set to 1FCCH / SCH superframe.

  Next, a different frequency component observation method between GSM and GSM will be described. FIG. 2 is a diagram for explaining the observation time of the GSM superframe applied to the GSM system. FIG. 3 shows a method for observing different frequency components between GSM and GSM. Specifically, FIG. 3A is a diagram illustrating the frame format of the common control channel, and FIG. 3B is a diagram illustrating the frame format of the individual traffic channel in relation to the common control channel. FIG. 4C is a diagram for explaining the observation time inserted for each superframe. FIG. 4 is a diagram for explaining an observation example in a dedicated traffic channel of the GSM system. This FIG. 4 is described in the literature name “The GSM System for Mobile Communication”, by Michel MOULY / Marie-Bernadette PAUTET, International Standard Book Number: 2-9507190-0-7.

  In the GSM system, the non-transmission time (idle time) allocated to one GSM superframe is 12 BP (= 6.9 ms) as shown in FIG. During handover, different frequency components (control channels) of other GSM systems are observed and detected using this non-transmission time. The aforementioned FCCH / SCH super frame is composed of 51 frames (see FIG. 3A). In contrast, the GSM superframe (see FIG. 3B) is 52 frames in two cycles. For this reason, when both superframes are compared, a difference of one frame occurs. That is, the FCCH / SCH superframe is deficient by one frame. Since the observation time is once per 1 GSM superframe, observation and detection are performed twice in the 2GSM superframe (see FIG. 3C).

  This observation and detection procedure is shown in FIG. In comparison between the 1FCCH / SCH superframe of the common control channel and the 2GSM superframe of dedicated traffic, there is a difference of one frame. In the dedicated traffic channel TACH / F, the position of the observation time assigned to 1 GSM superframe is fixed. Therefore, observation is performed in a predetermined frame of every GSM superframe. If the FCCH / SCH superframe is composed of the same number of frames as the 2GSM superframe, the same frame number is always observed between GSM and GSM, but between the FCCH / SCH superframe and the 2GSM superframe. Since there is a difference of one frame, it is possible to observe by shifting one frame at a time in each observation.

  In addition, since the GSM superframe corresponds to two cycles for one FCCH / SCH superframe, observation and detection are performed twice per one FCCH / SCH superframe. That is, since the opening of the pair of observation times becomes a 1 GSM superframe, the pair of observations proceeds with a shift of one period of the 1GSM superframe. Therefore, in frequency handover between GSM and GSM, observation and detection are performed twice per cycle of the FCCH / SCH superframe and while shifting by one frame every cycle.

  Next, UMTS, which is the next system, will be described. FIG. 5 shows a frame format applied to UMTS. Specifically, FIG. 5A is a diagram for explaining a frame format of an individual traffic channel applied to the GSM system, and FIG. 5B is a diagram for explaining a format of a UMTS superframe.

  In the GSM system, in the above-described dedicated traffic channel TACH, as shown in FIG. 5A, a cycle for transmitting frames as transmission units from # 1 to # 26 is a 1GSM superframe. One frame is 8 BP (Burst Period) time. On the other hand, in UMTS, a UMTS superframe is configured with the same cycle as this GSM superframe. That is, in UMTS, for all channels, as shown in FIG. 5B, a period for transmitting a 10 ms frame from # 1 to # 12 is set as a 1UMTS superframe.

  Next, a method for observing different frequency components between GSM and UMTS will be described. FIG. 6 shows a method for observing different frequency components between GSM and UMTS. Specifically, FIG. 6A is a diagram for explaining the frame format of the common control channel applied to the GSM system, and FIG. 6B is a diagram for explaining the superframe relationship between the UMTS and the GSM system. FIG. 6C is a diagram for explaining the observation time inserted for each superframe in UMTS.

  The aforementioned FCCH / SCH superframe is composed of 51 frames (see FIG. 6A). In contrast, the GSM superframe (see FIG. 3B) is 52 frames in two cycles. Since the GSM superframe and the UMTS superframe have the same time for one cycle, the relationship between the FCCH / SCH superframe and the UMTS superframe matches the relationship between the FCCH / SCH superframe and the GSM superframe already described. . That is, when the FCCH / SCH superframe and the 2UMTS superframe are compared, a difference of one frame is generated (see FIG. 6B).

  Here, also in the frequency handover between UMTS and GSM, in order to obtain the same function as the frequency handover between GSM and GSM described above, it is necessary to have an observation time of about 6.9 ms per UMTS superframe. Accordingly, as shown in FIG. 6C, two observations and detections are incorporated in the 2UMTS superframe. However, this is the same as the handover between GSM and GSM when 12BP = 6.9 ms.

  However, in the above handover between UMTS and GSM, it is impossible to allocate all the observation times necessary for one superframe in one frame due to error correction code and spreading factor restrictions. That is, the operation for increasing the coding rate of the error correction code cannot be increased beyond the number of information bits when not coding. In UMTS, the frame length is 10 ms, and the non-transmission time of about 6.9 ms for observing different frequency components is as long as half or more of the frame length, so that the interleave performance is expected to deteriorate. Furthermore, in order to prepare a non-transmission time of about 6.9 ms within one frame, it is necessary to compress the transmission time to about 3.1 ms, so the transmission power during the compressed mode transmission is inevitably increased. There is a problem that the interference power given to other channels is instantaneously increased.

  Therefore, it is conceivable that the observation and detection of the different frequency components per 1 UMTS superframe are performed in a plurality of times. At that time, the time performance for acquiring the control channel of the GSM system is the same as the case where the observation time is made once in one UMTS superframe. Thereby, the number of idle slots for obtaining the observation time per time is set to be smaller than that between GSM and GSM. This idle slot is generated by using a punctured code or error correction coding with a higher coding rate.

  In the first embodiment, a case where observation and detection are performed twice per 1 UMTS superframe is shown. For this reason, four observations and detections are performed in the 2UMTS superframe.

  This observation and detection method will be described with reference to FIG. FIG. 7 is a diagram illustrating downlink frame transmission according to Embodiment 1 of the present invention. In FIG. 7, the vertical axis represents transmission speed / transmission power, and the horizontal axis represents time. In comparison between the 1FCCH / SCH superframe and the 2UMTS superframe of the common control channel, there is a difference of one frame. In the dedicated traffic channel TACH / F, the position of the observation time assigned to the 1 GSM superframe is fixed, and similarly in UMTS, the position of the two observation times assigned to the 1UMTS superframe is fixed in the downlink traffic channel. . Therefore, observation and detection are performed in predetermined frames (two places) of each UMTS superframe. As described above, since there is a difference of 1 frame between the 1FCCH / SCH superframe and the 2UMTS superframe, the observation can be performed by shifting the frames one by one in each observation.

  In addition, since two cycles correspond to one FCCH / SCH superframe, observation and detection are performed four times per one FCCH / SCH superframe. That is, for each 1 UMTS superframe, a pair of observation time intervals are 1 UMTS superframes, so that the pair of observations is shifted by one frame of the 1FCCH / SCH superframe. Therefore, in frequency handover between UMTS and GSM, observation and detection are performed four times per cycle of the FCCH / SCH superframe and while shifting each frame by one frame in each observation.

  The observation time, that is, the idle slot is arranged at the center of a predetermined frame. Thereby, an interleaving effect can be obtained in compressed mode frame transmission. Furthermore, by increasing the coding rate in punctured coding and error correction coding, the redundancy is reduced, and a lot of idle time can be secured accordingly. In this case, since the amount of information to be transmitted is reduced, the spreading factor can be kept constant. That is, the interference noise characteristic can be maintained. Note that when transmitting a compressed frame, the characteristics deteriorate, and therefore, it is necessary to slightly increase the transmission power from the normal transmission power.

  Hereinafter, a specific mobile communication system will be described as an example. FIG. 8 is a block diagram showing a mobile radio communication system according to Embodiment 1 of the present invention. The mobile radio communication system includes a transmitter 1 and a receiver 2 and is provided in each of a base station and a mobile station. For example, a W (Wide Area) -CDMA (Code Division Multiple Access) communication system is applied to this mobile radio communication system.

  As shown in FIG. 8, the transmitter 1 includes a controller 11, an error correction encoder 12, an interleaver 13, a framing / spreader 14, a radio frequency transmitter 15, and the like. The controller 11 mainly controls the operations of the interleaver 13, the framing / spreader 14, and the radio frequency transmitter 15 through negotiation with the receiver 2. The controller 11 controls operations suitable for the normal mode (non-compression mode) and the compression mode by negotiation with the receiver 2. Specifically, the controller 11 instructs the framing / spreader 14 at the transmission timing for transmitting the compressed mode frame in the compressed mode. Further, the controller 11 instructs the radio frequency transmitter 15 to increase the average transmission power when transmitting the compressed mode frame.

  The error correction encoder 12 performs error correction encoding on the transmission data string to obtain encoded data. The interleaver 13 arranges the temporal order of the encoded data in units of bits in order to minimize the influence of transmission errors when, for example, consecutive bits of the transmission signal are lost during transmission due to fading. Change (interleave). The interleaver 13 has a memory for interleaving for one frame.

  The framing / spreader 14 spreads over a wide band using a spreading code for each user according to the normal mode and the compression mode, and forms a frame according to each mode. When instructed from the controller 11 to the transmission timing corresponding to each mode, the framing / spreader 14 sends a frame to the radio frequency transmitter 15 at the transmission timing. The radio frequency transmitter 15 converts the transmission signal obtained by the framing / spreader 14 into a radio frequency and transmits it. The radio frequency transmitter 15 increases the average transmission power in the compression mode and outputs a transmission signal as compared with the normal mode according to the control of the controller 11.

  As shown in FIG. 8, the receiver 2 includes a controller 21, an error correction decoder 22, a deinterleaver 23, a deframe / despreader 24, a radio frequency receiver 25, and the like. The controller 21 mainly controls the operations of the deinterleaver 23 and the deframer / despreader 24 through negotiation with the transmitter 1. The controller 21 controls operations suitable for each of the normal mode and the compression mode by negotiation with the transmitter 1. Specifically, the controller 21 instructs the deframe / despreader 24 to receive timing for receiving the compressed mode frame in the compressed mode.

  The radio frequency receiver 25 demodulates a reception signal transmitted from an antenna (not shown). The deframing / despreader 24 despreads using a spreading code assigned to the user of the receiver 2 in accordance with the normal mode and the compression mode, and forms a frame in accordance with each mode. When the deframing / despreading unit 24 is instructed by the controller 21 about the reception timing corresponding to each mode, the deframing / despreading unit 24 takes in the reception signal from the radio frequency receiver 25 at the reception timing.

  The deinterleaver 23 rearranges (deinterleaves) the temporal order of the encoded data in bit units in the reverse order to the interleaving in the transmitter 1. The deinterleaver 23 has a memory for interleaving for one frame, similar to the interleaver 13 described above. The error correction decoder 22 performs error correction decoding on the deinterleaved signal to obtain decoded data, that is, a received data string.

  Next, frame transmission including the compression mode will be described. In this mobile radio communication system, in the compression mode, a period is provided in which frames are slotted and transmitted intermittently, and the strength of other frequency carriers is measured using the non-transmission time during that period. For that purpose, it is necessary to compress the slotted frame, but if interleaving is performed in the same way as in normal transmission, the interleaving time is not sufficient, and it is impossible to obtain a sufficient interleaving effect. Become.

  Therefore, the transmission time of the compressed frame is divided within one frame, and one is assigned to the head of the frame frame and the other is assigned to the end of the same frame frame to secure a required interleaving target time. That is, an idle slot corresponding to the observation time is arranged at the center of the frame. In the receiver 2, this operation is reversed.

Here, the relationship between the number of idle slots and the number of slots in the compressed mode frame will be described. Considering one frame as 16 slots, assuming that the number of slots in the first half is A, the number of idle slots is B, and the number of slots in the second half is C, for example, the following combinations are possible. That is,
(A, B, C) = (7, 1, 8) / (7, 2, 7) / (6, 3, 7) /
(6,4,6) / (5,5,6) / (5,6,5)
It is. According to the above combination, for example, when the number of slots in the first half and the second half is 7 slots and 8 slots, respectively, one slot at the center of the frame is inserted as an idle slot.

  When a small idle slot is allocated so that the number of idle slots is 1 or 2 per frame, it is only necessary to deal with punctured coding. At this time, the position of the idle slot is basically the center of the frame, but may be shifted forward and backward.

  As described above, in a small idle slot, by appropriately determining the positions of the first half / second half compressed mode frame and the idle slot, it is possible to obtain the supplementary time performance equivalent to the frequency handover between GSM and GSM.

  In the first embodiment, within one frame, the compression mode frame is divided into two in the first half and the second half with an idle slot as a boundary. Therefore, a method for determining the insertion time in which frame in one UMTS superframe the observation time, that is, the idle slot is inserted will be described.

First, one UMTS superframe is composed of 12 frames. In GSM, one GSM superframe is composed of 26 frames and is 8 BP per frame, so that the total period is 208 BP. Further, since an idle slot corresponding to 8 BP is observed in two compression modes, it is an idle slot length corresponding to 4 BP that is observed in one compression mode. From the above relation, when the first frame is arbitrarily specified for the 1UMTS superframe, the following expression (1) shows the expression for specifying the position of the second frame from the first frame. This equation (1) shows a case where the first frame number is an even number and the second frame number is an odd number. Equation (1) is
4 (2n + 1) = K (208BP) / 12
2n + 1 = 13K / 3 (1)
It becomes. In the expression (1), the place where the first half compression mode can be observed is the same, but since the observation time length is 4BP which is half of 8BP, the 4BP portion which can be observed in the second half compression mode is missing in the first half. The relational expression for equivalently observing 4BP corresponding to the latter half of 8BP is shown. That is, 4 (2n + 1) indicates an odd multiple of 4BP (when the first half is an even number, the second half is an odd number), suggesting that the interval should be K times the UMTS frame length. . Here, when the UMTS frame length is expressed in BP, it becomes 208 BP (the number of BPs in the UMTS superframe) / 12 (the number of UMTS frames included in the UMTS superframe). Note that n is an arbitrary natural number.

When a combination of K and n satisfying the above equation (1) is obtained, two types of combinations are obtained as in the following equation (2). That is,
(K, n) = (3, 6) / (9, 19) (2)
It becomes. According to Equation (2), the frame after 3 frames from the first frame may be the second frame, or the frame after 9 frames from the first frame may be the second frame. For example, in FIG. 7, if frame # 2 is the first frame, frame # 5 is the second frame.

  Next, the compressed mode operation when performing observation and detection from the UMTS to the GSM system will be described. Here, only the compression mode will be described. FIG. 9 is a flowchart for explaining the transmission operation in the compression mode, and FIG. 10 is a flowchart for explaining the reception operation in the compression mode. In the compression mode by the transmitter 1 on the UMTS side (see FIG. 9), interleaving in one frame is instructed to the interleaver 13 (step S101), and interleaving is performed in one frame in the interleaver 13. When the first frame timing or the first half timing or the second half timing of the second frame timing to be observed is reached (step S102), the transmission timing is instructed to the framing / spreader 14. (Step S103).

  Further, the radio frequency transmitter 15 is instructed to increase the average transmission power (step S104), and the frame transmission is performed with a higher transmission power than the normal mode for the compressed mode frame. In this way, two observations and detections are performed within one UMTS superframe. In the compression mode, frames are transmitted intermittently (discontinuously).

  On the other hand, in the compression mode by the receiver 2 on the UMTS system side (see FIG. 10), when the first frame timing to be observed or the first half timing or the second half timing of the second frame timing is reached (step S111). ), The reception timing is instructed to the deframe / de-spreader 24 (step S112). After receiving a signal for one frame, deinterleaving by one frame is instructed to the deinterleaver 23 (step S113), and the deinterleaver 23 performs deinterleaving in one frame. In this way, in the compressed mode, frames are received intermittently (discontinuously), and the GSM system signal is observed in the free time.

  As described above, according to the first embodiment, when UMTS and another system coexist, ½ of the amount of one frame constituting the superframe is maximized with respect to the UMTS superframe. In addition, idle time for observing the frequency components of other systems is inserted at intervals of a predetermined number of frames. As a result, it is not necessary to observe the frequency component in one observation within one superframe, and it is possible to satisfy restrictions on error correction codes and spreading factors on frame transmission. As a result, even if the UMTS and another system coexist, the frequency components of the other system can be reliably observed from the UMTS, and at that time, it is possible to suppress the deterioration of the interleave performance of the compressed mode frame.

  In addition, in one UMTS superframe, the predetermined frame number interval is determined by the difference in the transmission period between the UMTS and the other systems, so that it is possible to observe different frequency components without depending on the difference in the transmission period. is there.

  Further, since the idle slot time is arranged at the center of the frame which is a unit of the UMTS superframe, it is possible to reliably obtain the interleaving effect.

  Also, since a plurality of idle times are arranged for each frame in the UMTS superframe, it is possible to secure the required idle time in one superframe.

  Moreover, since the total of the plurality of idle slot times is set to about 6.9 ms, equivalent to GSM, it is possible to secure free time equivalent to the different frequency observation between other systems in one UMTS superframe. is there.

  In addition, since frames with idle slot time inserted are compressed and transmitted intermittently, frame transmission with high reproducibility can be realized even if idle time is inserted within one frame period. Is possible.

  In addition, since the compressed frame is generated by increasing the coding rate, the compression rate is reduced, and the number of spreading codes having a shorter sequence length can be suppressed.

  In addition, since the frame compressed with the same spreading factor as that in the normal mode is generated in the compression mode, the anti-interference noise characteristic can be maintained for the compressed frame.

  In addition, since the average transmission power is increased during compressed mode frame transmission, it is possible to minimize the deterioration of characteristics.

Embodiment 2. FIG.
In Embodiment 1 described above, at the time of frequency handover, the observation time (about 6.9 ms) is divided into two frames in one UMTS superframe, and observation and detection are performed in two frames. The present invention is not limited to this, and the observation time may be divided more than two divisions as in the second embodiment described below. In the second embodiment, four divisions are taken as an example. In the second embodiment, the overall configuration is the same as that of the first embodiment described above, and only differences in operation will be described in the following description.

  Here, the observation and detection method of the second embodiment will be described. FIG. 11 is a diagram for explaining downlink frame transmission according to Embodiment 2 of the present invention. In FIG. 11, the vertical axis represents transmission speed / transmission power, and the horizontal axis represents time. As described above, there is a difference of one frame in comparison between the 1FCCH / SCH superframe and the 2UMTS superframe of the common control channel. In the dedicated traffic channel TACH / F, the position of the observation time assigned to the 1 GSM superframe is fixed, and in the UMTS, the position of the four observation times assigned to the 1UMTS superframe is fixed in the downlink traffic channel as well. . Therefore, observation and detection are performed in predetermined frames (four locations) of each UMTS superframe. Thus, there is a difference of one frame between the FCCH / SCH superframe and the 2UMTS superframe, so that the observation can be performed by shifting the frames one by one in each observation.

  In addition, since two cycles correspond to one FCCH / SCH superframe, observation and detection are performed eight times per one FCCH / SCH superframe. That is, for each 1 UMTS superframe, a pair of observation time intervals are 1 UMTS superframes, so that the pair of observations is shifted by one period of the 1UMTS superframe. Therefore, in frequency handover between UMTS and GSM, observation and detection are performed eight times per cycle of the FCCH / SCH superframe and while shifting each frame by one frame in each observation.

  Also in the second embodiment, as in the first embodiment described above, the compressed mode frame is divided into two in the first half and the second half with an idle slot as a boundary in one frame. Therefore, a method for determining the insertion time in which frame in one UMTS superframe the observation time, that is, the idle slot is inserted will be described.

  In the first embodiment described above, since 1 UMTS superframe is composed of 12 frames, the UMTS superframe is divided by the number of frames. However, the UMTS superframe is divided into smaller time units and idle slots are arranged. The position may be set. For example, since one frame in UMTS is composed of 16 slots, the second embodiment takes a method of dividing by the number of slots.

For the above reason, the following formula (3) shows the formula in the case of four divisions. In this case, the first to fourth frames to which the observation time is assigned are necessary. Equation (3) shows a case where the frame number of the first frame is an even number. Expression (3) is an expression for obtaining the second frame. Similar to the idea in the first embodiment, this equation (2) is
2 BP (4n + 1) = K1 (208 BP ) / ( 12 × 16 )
4n + 1 = 13K1 / 24 (3)
It becomes. In Equation (3), K1 indicates the frame number of the second frame of the UMTS superframe, and n is an arbitrary natural number. In the right side of equation (3), since one frame is 16 slots, 12 frames are multiplied by the denominator.

When the combination of K1 and n satisfying the above equation (3) is obtained, two types of combinations are obtained as in the following equation (4). That is,
(K1, n) = (24, 3) / (120, 16) (4) In this case, since K1 = 24 represents the number of slots, the second frame can be obtained by dividing K1 by 16. Therefore, when K1 = 24, a solution of 1.5 frames can be obtained. Therefore, when represented by a frame number, the frame to which the second observation time is assigned is a frame after 1.5 frames of the first frame. .

Expression (5) is an expression for obtaining the third frame. This equation (5) is
2 (4n + 2) = K2 (208BP) / 12 × 16
2n + 1 = 13K2 / 48 (5)
It becomes. In Equation (5), K2 indicates the frame number of the third frame of the UMTS superframe, and n is an arbitrary natural number.

When a combination of K2 and n satisfying the above equation (5) is obtained, two types of combinations are obtained as in the following equation (6). That is,
(K2, n) = (48,6) / (144,19) (6)
It becomes. In this case, since K = 48 represents the number of slots, the third frame can be obtained by dividing K by 16. Therefore, when K = 48, a solution of 3 frames is obtained, so that the frame to which the third observation time is assigned is a frame that is 3 frames after the first frame.

Expression (7) is an expression for obtaining the fourth frame. This equation (7) is
2 (4n + 3) = K3 (208BP) / 12 × 16
2n + 1 = 13K3 / 48 (7)
It becomes. In Equation (7), K3 represents the frame number of the fourth frame of the UMTS superframe, and n is an arbitrary natural number.

When a combination of K3 and n satisfying the above equation (7) is obtained, two types of combinations are obtained as in the following equation (8). That is,
(K3, n) = (72, 9) / (168, 22) (8)
It becomes. In this case, since K = 72 represents the number of slots, the fourth frame can be obtained by dividing K by 16. Therefore, when K = 72, a solution of 4.5 frames can be obtained. Therefore, when represented by the frame number, the frame to which the fourth observation time is assigned is the frame after 4.5 frames of the first frame. .

  As described above, according to the second embodiment, the number of observation time divisions in one UMTS superframe may be four. In this case as well, the same effect as in the first embodiment described above can be obtained. Can do. However, as in the first embodiment, the division interval is not a predetermined frame interval, but is a predetermined slot number interval.

Embodiment 3 FIG.
In Embodiment 2 described above, at the time of frequency handover, the observation time (about 6.9 ms) is divided into 4 frames in 1 UMTS superframe, and observation and detection are performed in 4 frames. The present invention is not limited to this, and the observation time may be divided more than four divisions as in the third embodiment described below. In the third embodiment, eight divisions are taken as an example. In the third embodiment, the overall configuration is the same as that of the first embodiment described above, and only differences in operation will be described in the following description.

  Here, the observation and detection method of the third embodiment will be described. FIG. 12 is a diagram for explaining downlink frame transmission according to Embodiment 3 of the present invention. In FIG. 12, the vertical axis represents transmission speed / transmission power, and the horizontal axis represents time. As described above, there is a difference of one frame in comparison between the 1FCCH / SCH superframe and the 2UMTS superframe of the common control channel. In the dedicated traffic channel TACH / F, the position of the observation time assigned to the 1 GSM superframe is fixed, and similarly in UMTS, the position of the eight observation times assigned to the 1UMTS superframe is fixed in the downlink traffic channel. . Therefore, observation and detection are performed in predetermined frames (four locations) of each UMTS superframe. Thus, there is a difference of one frame between the FCCH / SCH superframe and the 2UMTS superframe, so that the observation can be performed by shifting the frames one by one in each observation.

  Further, since two periods correspond to one FCCH / SCH superframe, observation and detection are performed 16 times per one FCCH / SCH superframe. That is, for each 1 UMTS superframe, a pair of observation time intervals are 1 UMTS superframes, so that the pair of observations is shifted by one period of the 1UMTS superframe. Therefore, in frequency handover between UMTS and GSM, observation and detection are performed 16 times per cycle of the FCCH / SCH superframe and while shifting each frame by one frame in each observation.

  Also in the third embodiment, as in the first and second embodiments, the compressed mode frame is divided into two in the first half and the second half with an idle slot as a boundary in one frame. Therefore, a method for determining the insertion time in which frame in one UMTS superframe the observation time, that is, the idle slot is inserted will be described.

  In the third embodiment, as in the second embodiment described above, the UMTS superslam is divided in finer time units, and the positions at which idle slots are arranged are set.

  Thus, according to the third embodiment, the number of observation time divisions in one UMTS superframe may be eight divisions, and in this case, the same effect as in the first embodiment can be obtained. . However, as in the first embodiment, the division interval is not a predetermined frame interval, but is a predetermined slot number interval.

  In Embodiments 1 to 3 above, the observation time has been described up to eight divisions. However, the present invention is not limited to this, and a unit smaller than a slot is used as a reference according to the number of divisions. The number of divisions may be further increased.

  As mentioned above, although this invention was demonstrated by the said embodiment, a various deformation | transformation is possible within the range of the main point of this invention, and these are not excluded from the scope of this invention.

  As described above, the mobile radio communication system according to the present invention is useful for a system in which a UMTS (Universal Mobile Terrestrial Communication System) and a GSM (Group Specific Mobile) system coexist, and particularly in a mobile radio communication system. It is suitable for a communication apparatus that observes a control channel of a GSM system, which is another system, using idle time.

It is a figure which shows the frame format applied to a GSM system. It is a figure explaining the observation time of the GSM superframe applied to a GSM system. It is a figure which shows the observation method of the different frequency component between GSM-GSM. It is a figure explaining the observation method in a GSM system. It is a figure which shows the frame format applied to UMTS. It is a figure which shows the observation method of the different frequency component between GSM-UMTS. It is a figure explaining the frame transmission of the downlink by Embodiment 1 concerning this invention. 1 is a block diagram showing a mobile radio communication system according to a first embodiment of the present invention. It is a flowchart explaining the transmission operation | movement at the time of the compression mode by Embodiment 1 concerning this invention. It is a flowchart explaining the receiving operation at the time of the compression mode by Embodiment 1 concerning this invention. It is a figure explaining the frame transmission of the downlink by Embodiment 2 concerning this invention. It is a figure explaining the frame transmission of the downlink by Embodiment 3 concerning this invention. It is a figure explaining the frame transmission of the conventional downlink.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Transmitter 2 Receiver 11 Controller 12 Error correction encoder 13 Interleaver 14 Framer / spreader 15 Radio frequency transmitter 21 Controller 22 Error correction decoder 23 Deinterleaver 24 Deframer / Despreader 25 Radio Frequency receiver

Claims (4)

A period required to transmit a first specific number of first frames consisting of a predetermined number of slots and having a first frame length L1 is defined as a first transmission period, and the first transmission period is a unit. A first CDMA (Code Division Multiple Access) communication system comprising: a transmitter that continuously transmits the first frame; and a receiver that receives the first frame transmitted by the transmitter;
A frame in a communication scheme in which a second transmission period is a period required to transmit a second specific number of second frames having the second frame length L2 and is not an integral multiple of the first transmission period. A second communication system for performing transmission;
In the mobile radio communication method employed by the receiver of the first communication system in the mobile radio communication system in which
Transmitter of the first communication system, the first transmission cycle in the a plurality of non-transmission time, no transmission is corresponding portions the interval between the non-transmission time one and the other non-transmission time The non-transmission time interval is determined in units of the number of slots so that the time interval corresponds to a value obtained by dividing the second frame length L2 by a predetermined even number and an odd number, and the determined non-transmission time interval The first frame sent to the receiver with no transmission time at
Receiving step for receiving,
An observation step of observing a control data transmission channel of the second communication system during the non-transmission time ;
A mobile radio communication method comprising: The first frames received in the reception step are P frames having a length equal to or less than ½ of the first frame length L1 within the first transmission period by the transmitter of the first communication system. P is an even number) and the non-transmission time interval is set to the number of slots so that the non-transmission time interval is closest to (L2 / P) × (P × n + 1) (n is a natural number). The first frame transmitted to the receiver with the non-transmission time being arranged at the determined non-transmission time interval,
  The mobile radio communication method according to claim 1. A period required to transmit a first specific number of first frames consisting of a predetermined number of slots and having a first frame length L1 is defined as a first transmission period, and the first transmission period is a unit. A first CDMA (Code Division Multiple Access) communication system comprising: a transmitter that continuously transmits the first frame; and a receiver that receives the first frame transmitted by the transmitter;
  A frame in a communication scheme in which a second transmission period is a period required to transmit a second specific number of second frames having the second frame length L2 and is not an integral multiple of the first transmission period. A second communication system for performing transmission;
  In the receiver of the first communication system in the mobile radio communication system in which
  The transmitter of the first communication system provides a plurality of no-transmission times within the first transmission period, and no-transmission is an interval between corresponding portions of one no-transmission time and another no-transmission time. The non-transmission time interval is determined in units of the number of slots so that the time interval corresponds to a value obtained by dividing the second frame length L2 by a predetermined even number and an odd number, and the determined non-transmission time interval The first frame sent to the receiver with no transmission time at
  Receive
  Observe the control data transmission channel of the second communication system during the no-transmission time
A receiver characterized by that. The first frames to be received are P frames in which the transmitter of the first communication system has a length equal to or less than ½ of the first frame length L1 within the first transmission period (P is an even number). ) And the non-transmission time interval is determined in units of the number of slots so that the non-transmission time interval is closest to (L2 / P) × (P × n + 1) (n is a natural number). The first frame transmitted to the receiver by arranging no-transmission time at the determined no-transmission time interval,
  The receiver according to claim 3.

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