JP4699203B2 - Wireless communication apparatus and wireless communication system - Google Patents

Description

  The present invention relates to a radio communication apparatus capable of receiving data by radio and receiving satellite signals from a satellite, and a radio communication system having the radio communication apparatus and a base station.

In a general GPS (global positioning system) signal reception system, the transmission / reception antenna for data and telephone communication (hereinafter simply referred to as data communication) and the GPS antenna are the same. There is no shielding. However, if the antenna is shielded, both data communication and GPS signal reception are impossible.
A diversity reception system is known as a technique for switching between the antennas to be used by providing a plurality of antennas in order to cope with such shielding of the antennas or to improve the reception sensitivity.
The diversity reception method is generally a method in which GPS reception cannot be performed during data communication, but there is a method suitable for high-speed data communication in which data communication and GPS signal reception are performed simultaneously or individually.

A GPS-compatible radio communication device having an antenna switching module that switches between two antennas for a radio signal transmission / reception circuit and a GPS reception circuit is known as a diversity type device capable of detecting a position by GPS (for example, a patent) Reference 1).
This GPS-compatible wireless communication device is equipped with two antennas having different directivities and an antenna switching module. When one of the two antennas receives a radio signal by the antenna connection control of the antenna switching module, the other is The GPS signal can be received.
In this configuration, even when one of the two antennas is interfered with radio wave reception by a human hand or other obstacle, one of the radio signal and the satellite signal can be received by switching to the other antenna.
Special table 2005-518708 (see FIG. 1A and the corresponding description)

However, in the field of mobile communication such as mobile terminals, for example, services are generally performed that receive radio waves from a satellite to detect the position and display the detected position on a map. In that case, in order to display the current position quickly, it is necessary to receive data such as map information without switching the antenna when receiving a GPS signal (satellite signal).
If the technique of Patent Document 1 is applied to such a field, the antenna can be switched to an antenna having a good reception state, but there is a disadvantage that data cannot be received when a satellite signal is received. Therefore, it is necessary to frequently switch the antenna at the time of receiving a GPS signal and at the time of data reception, and the processing speed and processing load are large.

  The problem to be solved by the present invention is to enable data reception and satellite signal reception both when receiving with one of the two antennas and when receiving with the other.

The wireless communication apparatus according to the present invention is not connected to the first antenna, the second antenna, and the second antenna, but connected to the first antenna and received by the first antenna. A first receiving circuit for receiving a signal, and a second receiving circuit for receiving a radio signal connected to the second antenna and received by the second antenna without being connected to the first antenna . A receiving circuit; switching means for switching connection to any one of the first antenna and the second antenna; the first antenna and the second antenna connected via the switching means; A satellite reception circuit that performs reception processing of a satellite signal received by any one of the above and a signal processed by at least one of the first reception circuit and the second reception circuit are input to perform signal processing. Signal processing means; A satellite signal processing means for performing by the input signal processing satellite signals processed by the serial satellite receiver circuit, characterized in that it comprises a.

In the present invention, preferably, a first demultiplexing unit for demultiplexing a signal received by the first antenna is provided between the first antenna and the switching unit, and the second antenna and the switching unit are provided. And a second demultiplexing means for demultiplexing a signal received by the second antenna.
In the present invention, preferably, the apparatus further comprises reference signal output means capable of outputting a plurality of reference signals, and the second receiving circuit includes a radio signal received by the second antenna and one reference output from the reference signal output means. A first mixing means for mixing the signal, and the satellite receiving circuit comprises a second mixing means for mixing the satellite signal and the other one of the reference signals output from the reference signal output circuit. It is characterized by that.
Preferably, in the present invention, when the satellite reception circuit is connected to the first antenna via the switching means, the satellite signal reception process is performed regardless of the radio signal reception process in the first reception circuit. It is characterized by doing.
Preferably, in the present invention, when the antenna connected to the satellite reception circuit is switched by the switching unit, the satellite signal processing unit sets the reception start timing of the satellite signal from the satellite to the same timing as before switching. It is characterized by doing.
In the present invention, preferably, when the antenna connected to the satellite receiving circuit is switched by the switching unit, the satellite signal processing unit controls the reception start timing of the satellite signal from the satellite independently from before switching. It is characterized by doing.

  In the wireless communication system according to the present invention, a wireless communication device having any one of the above features further includes: a transmission circuit that transmits data acquired in the reception process of the satellite reception circuit to a base station; and the switching unit. When the antenna connected to the satellite receiving circuit is switched, transmission control means for controlling transmission start timing of the data from the transmitting circuit is received, and the data transmitted by the transmitting circuit is received. The base station further comprises position information calculation means for calculating position information based on the data.

The wireless communication apparatus according to the present invention has an advantage that data reception and satellite signal reception can be performed simultaneously when receiving with one of the two antennas and receiving with the other.
In addition, since the wireless communication apparatus according to the present invention includes the wireless communication apparatus and the base station having the above advantages, there is an advantage that the position information via the base station can be calculated.

  Hereinafter, embodiments of a wireless communication apparatus and a wireless reception control method of the present invention will be described.

A feature of the present invention is that data such as map data can be received through a signal processing path (path) of an antenna that performs GPS reception.
As a configuration for this, a wireless communication device according to the present invention includes first and second antennas, a first receiving circuit connected to the first antenna, and a second receiving circuit connected to the second antenna. The antenna switching means, the satellite receiving circuit connected to one of the first antenna and the second antenna by the switching means, and at least one of the first receiving circuit and the second receiving circuit. Signal processing means for inputting the received signal and performing signal processing, and satellite signal processing means for inputting the satellite signal processed by the satellite receiving circuit and performing signal processing. These specific embodiments will be clarified in the following description.

FIG. 1 shows a configuration example of a wireless communication apparatus that can always secure a data reception processing path. The wireless communication apparatus of the present invention is not limited to the configuration shown in FIG.
A wireless communication device (wireless communication terminal) 1 shown in FIG. 1 includes a main antenna 2A as a first antenna, a sub-antenna 2B as a second antenna, and three demultiplexers (demultiplexing means) 3a1, 3a2, and 3b. Switching means 4, transmission circuit 5, two CDMA reception circuits 6A and 6B as first and second reception circuits, GPS reception circuit 7 as a satellite reception circuit, signal processing means and satellite signal processing means And a control / processing circuit 8 having the following functions.
Each of the CDMA reception circuits 6A and 6B includes a first amplifier 61, a filter 62, a second amplifier 63, a CDMA down converter 64, and a local associated circuit 65A or 65B including a local oscillator.
The GPS receiving circuit 7 includes a first amplifier (LNA: low noise amplifier) 71, a filter 72, a second amplifier 73, and a GPS down converter 74.

In this example, the local related circuit 65B included in the CDMA receiving circuit 6B is different from the local related circuit 65A included in the CDMA receiving circuit 6A, and the frequency oscillation function between GPS reception and normal (terrestrial radio) reception can be switched. Therefore, it is shared by both receptions. As a result, an increase in circuit scale is suppressed and cost reduction is achieved.
This sharing is optional, and a local related circuit may be provided in each of the GPS receiving circuit 7 and the CDMA receiving circuit 6B. In that case, the sub-antenna 2B may receive the terrestrial radio signal and the GPS signal at the same time, and the control / processing circuit 8 is configured so that both of the acquired signals can be processed in parallel.

  The wireless communication terminal 1 having such a configuration can be connected to the GPS receiving circuit 7 by switching either the reception processing path from the main antenna 2A or the reception processing path from the sub antenna 2B by the switching means 4. This antenna switching is hereinafter referred to as diversity switching operation (or simply diversity).

  In an initial state before diversity is performed, the GPS receiving circuit 7 is connected to the sub antenna 2B side, and the CDMA receiving circuit 6A is connected to the main antenna 2A side. This is because the main antenna connected to the CDMA reception circuit 6A side having the transmission circuit 5 must support both the transmission band and the reception band, and only the reception band than the main antenna. This is because the antenna characteristics at the time of detecting the GPS position are more easily obtained by performing GPS correspondence with the sub-antenna. Also, in order to alleviate the interference caused by the transmission wave transmitted by itself, it is better to support the GPS with the sub antenna.

In this initial state, the CDMA receiving circuit 6A can receive data carried by the terrestrial radio signal from the main antenna 2A, and the CDMA receiving circuit 6B can receive data from the sub-antenna 2B. However, once GPS reception starts, in the illustrated example in which the local related circuit 65B is shared, data reception during GPS reception is possible on the CDMA receiving circuit 6A side, but the local related circuit 65B supports GPS reception. Since it is switched as much as possible, it is impossible on the CDMA receiving circuit 6B side. On the other hand, when the local related circuit 65B is not shared, both antennas (the main antenna 2A and the sub-antenna 2B) can continue to receive data even during GPS reception after diversity.
Note that the data in this specification includes at least one of voice data including a call such as a mobile phone, image data, and text data.

As described above, in the configuration of FIG. 1, in the initial state, the CDMA reception circuit 6A side connected to the main antenna 2A, and in the initial state, the CDMA reception circuit 6B side connected to the sub-antenna 2B, the CDMA reception circuit 6A side. Only the transmission circuit 5 has a simple configuration. Also in such a simple configuration, GPS reception is possible on any one of the main antenna 2A and the sub-antenna 2B. When GPS reception is performed using the main antenna 2A, terrestrial radio signal data can be received by the main antenna 2A performing GPS reception.
It is important that the main antenna 2A, which is one of the plurality of antennas, can perform both GPS reception and data reception. This point will be described below.

The wireless communication terminal 1 in FIG. 1 may be a portable terminal or a mobile terminal mounted in an automobile or the like, but the case of a portable terminal such as a cellular phone will be considered below.
In the case of a portable terminal, for example, an antenna arrangement as shown in FIG. 2 is possible. In FIG. 2, the main antenna 2A of FIG. 1 is divided into a GPS antenna 2Ag and a data communication main antenna 2Am, and the sub antenna 2B is divided into a GPS antenna 2Bg and a data communication sub antenna 2Bs. May have. FIG. 2 shows a demultiplexing circuit 3a2, a transmission circuit 5, a CDMA reception circuit 6A, and a GPS reception circuit 7 as other main configurations, and other configurations in FIG. 1 are omitted.

  In the portable terminal, as shown in FIG. 2 (A), the main antenna 2A (the GPS antenna 2Ag and the data communication main antenna 2Am) may be covered with the hand 100, or as shown in FIG. 2 (B). In addition, the sub antenna 2B (the GPS antenna 2Bg and the data communication sub antenna 2Bs) may be covered with the hand 100. If the antenna is covered with the hand 100 as described above, position measurement cannot be performed, or position detection accuracy decreases. Moreover, in a mobile terminal, which antenna has good reception characteristics may be determined depending on how it is held, and the situation is likely to change frequently. For this reason, for example, if reception characteristics are poor due to one of the antennas being covered with the hand 100, GPS reception is performed with the other antenna, and map data such as EZ Navi Walk (trademark) is used. It is necessary to display information on the current position on the display unit. The configuration of FIG. 1 answers this need.

Next, the GPS reception method will be described.
First, four GPS reception systems are shown in FIG. Of these, the Simultaneous method shown in FIGS. 3C and 3D is most desirable in that data reception processing can be performed even during GPS reception as described above. The configuration shown in FIG. 1 can receive GPS signals using the methods shown in FIGS. 3C and 3D. In addition, the system shown in FIGS. 3A and 3B can be executed by mode selection or the like even in the configuration of FIG. 1 by setting the mode in which data reception is paused or not performing position detection via the server. It is.

The processing of each method will be described with reference to FIGS. Here, a description will be given using time slots in which time is divided every predetermined time. However, a similar GPS reception process can be performed by performing each process at the same timing even in a communication system such as the CDMA communication system that does not have a concept of a time slot.
Here, “(time) slot” is a unit representing the size or processing time of a series of data groups used for a certain process. Accordingly, the slot length (data length or processing time) varies depending on the processing. However, in FIG. 3, the slot length is shown to be constant in order to improve the visibility. In the description here, FIG. 1 is referred to as appropriate. The wireless communication terminal 1 can be communicably connected to the position detection server via a wireless communication network (network) (not shown).
Here, the processing path (Path) is defined. Hereinafter, “path 1” means a signal processing path (path) of the main antenna 2A. Further, hereinafter, “path 2” means a signal processing path (path) of the sub-antenna 2B. Therefore, the GPS receiving circuit 7 also changes the signal processing path (path) according to the antenna connected with the diversity. That is, the GPS receiving circuit 7 of FIG. 1 can belong to the processing path (path 1) on the main antenna 2A side or the processing path (path 2) on the sub antenna 2B side by the operation of the switching unit 4. You can also.

The method shown in FIG. 3A is called an “MS-Assisted method”, and data can be received simultaneously on path 1 (Path 1) and path 2 (Path 2). It is a method to perform.
Specifically, the GPS reception path 7 in FIG. 1 is connected to the main antenna 2A by the operation of the switching unit 4, and as shown in FIG. 3A, in the path 1 at the timing of the slot S1. The GPS reception circuit 7 (FIG. 1) receives a satellite signal (GPS signal) from the satellite. At the timing of the next slot S2, the acquired satellite data is wirelessly transmitted to the server (base station), the position is calculated by the server, and the terminal receives the calculated position data from the base station by wireless. Thereafter, data reception (for example, EVDO (Evolution Data Only) reception) using the CDMA reception circuit 6A of path 1 is performed until the next position detection timing (at the start of the slot S5) (slots S3 and S4). Although only “data reception (EVDO reception)” is shown in the figure, data transmission (for example, EVDO transmission) may be performed in this slot. As described above, the MS-Assisted path 1 repeats GPS reception, communication with a server for position detection, and normal data transmission / reception.
On the other hand, in the path 2 in FIG. 3A, the GPS reception period (slots S1, S5, S9,...) And the transmission / reception period (slots S2, S6, S10,. Normal, ie, terrestrial radio data reception during the rest period between dormant states. This setting of the dormant state is because the GPS receiving circuit 7 and the CDMA receiving circuit 6B share the local related circuit 65B.

The method shown in FIG. 3B is called an “MS-Based method”, and is common to the method shown in FIG. 3A in that GPS signals are intermittently received only in Path 1 (Path 1). The first position detection process indicated by the slots S1 to S4 causes the server to perform accurate position calculation, and this process is the same as the MS-Assisted method of FIG.
However, after that, the position detection process via the server is not repeated, but simple detection position correction is performed in the wireless communication apparatus. That is, when GPS reception is performed in the path 1 at the timing of the slot S5, a process for correcting the position in the terminal is executed based on the satellite data. If this simple correction is performed several times, the error becomes large. In this example, after performing simple correction twice in slots S5 to S10 (this number is arbitrary), the same as in the first slots S1 to S4. By executing the position calculation on the server, an accurate position with a small error is acquired. On the other hand, it is the same as the MS-Assisted method that the data reception in the path 2 at the timing of both the GPS reception in the path 1 and the communication with the server for position detection is in the dormant state.
This MS-Based method reduces the number of communications with the server compared to the MS-Assisted method described above, and accordingly, normal data reception (and data transmission by terrestrial radio) to acquire maps and the like. Is possible.

  As apparent from FIGS. 3A and 3B, the above two methods have a high frequency of dormant states, and there is a limit to high-speed reception of map data and the like. In contrast to these two methods, there are the following two methods.

The method shown in FIG. 3C is called a “Simultaneous method”, and is common to the method shown in FIG. 3B in that simple detection position correction is performed.
The simultaneous method differs from the MS-Based method in that data reception is possible at the same timing (time slot) during GPS reception (satellite data reception). That is, GPS reception may be performed on the path 1 side as in FIG. 3 (B), or GPS reception may be performed on the path 1 side as shown in FIG. 3 (C), and either side. Even if GPS reception is performed, the fact that data reception can be performed on either side is a major feature of the simultaneous method. For this purpose, it is necessary to provide a signal processing circuit (control / processing circuit 8) capable of parallel processing GPS reception processing and data transmission / reception.
Specifically, the GPS receiving circuit 7 of FIG. 1 is in a state of being connected to the sub-antenna 2B by the operation of the switching means 4, and the slots S1 and S5 that are performing GPS reception in the path 2 of FIG. , S9,..., Data can be received on the same path 2 during the remaining period. At this time, the GPS receiving circuit 7 is connected to the sub-antenna 2B under the control of the switching means 4 and is controlled to belong to the path 2.
In the slot configuration example of this example, since only the path 1 has a data transmission function, the satellite data obtained by GPS reception in the path 2 is the next slot of the path 1, that is, the slots S2 and S6 in the above example. , S10,... Is transmitted to the server via the path 1, and the position calculation result by the server is received by the signal receiving circuit of the path 1. An arrow in FIG. 3C represents data transfer for that purpose. Data can be received in pass 2 during the period of the slots S2, S6, S10,..., But it is assumed that the data is a map or the like. Reception is started.

Compared with the MS-Based method, this Simultaneous method has an advantage that both GPS reception on one side path and data reception on the other side path can be performed simultaneously. Specifically, when the reception state of the main antenna 2A is poor in the initial state, in the path 2 in the initial state, GPS reception in the path using the sub antenna 2B and data reception in the path 1 using the main antenna 2A are performed. Both are possible.
In addition, the Simultaneous method can receive data such as a map at a high speed because the number of times data can be received is increased because the number of pauses is small.

The above three methods perform position calculation by the server for each GPS reception, or perform position calculation via the server at a rate of once every several GPS receptions, and perform simple correction at other GPS receptions. It is assumed.
On the other hand, in the method shown in FIG. 3D, data acquired from a satellite is processed by a terminal and a position is calculated in the terminal. This method is called “Stand Alone method”.
In the Stand Alone method, as shown in FIG. 3D, the position detection calculation is executed in the terminal following the GPS reception in each of the slots S1, S4, S7,. In other slots, data reception is possible. On the other hand, data (or data for GPS display or the like) can be received (or transmitted) in the path 1 regardless of the GPS processing in the path 2. In this method, since the position calculation processing performed by the server in another method is performed by the terminal, the position calculation in the terminal requires accurate accuracy.
This Stand Alone method does not require communication to “send satellite data to the server” compared to the above-mentioned Simultaneous method, so the number of times (number of slots) that can be received such as maps is further increased. Although increasing, the processing burden on the terminal is relatively large.
In addition, although the four GPS reception systems were described in the case of two reception processing paths (paths), three or more may be used.

The wireless communication apparatus 1 shown in FIG. 1 has a configuration most suitable for a diversity system that switches antennas for performing GPS reception in the simultaneous system that can simultaneously perform data reception and GPS reception in FIG. is there.
Further, the antenna switching control performed by the switching means 4 of FIG. 1 and the control unit in the control / processing circuit 8 that controls the switching means 4 is actually performed using, for example, the electric field strength of the GPS band at each antenna and the GPS signal from each antenna. The result of positioning (such as position detection accuracy) may be used, but a method of obtaining the number of captured satellites at each antenna by the control unit and switching to the antenna with the larger one is more desirable. Regarding the calculation of the number of captured satellites, for example, a satellite signal called a C / A code is multiplied by a unique code within the control unit, and a difference between the results, for example, a GPS signal whose multiplication result is at a high level, It is good to detect the number of satellites according to the number of types. In addition, it is possible to adopt a method of identifying the number of satellites from the transmission time information of the satellite signal transmitted from each satellite and the current position information of the satellite.
When the determination criterion is electric field strength, the switching means 4 is controlled so that an antenna from which a GPS signal with higher electric field strength can be obtained is connected to the GPS receiving circuit 7. Further, when the determination criterion is position detection accuracy, the switching unit 4 is controlled so that the antenna having the higher detected position accuracy is connected to the GPS receiving circuit 7. When the determination criterion is the number of satellites, the switching unit 4 is controlled so that an antenna having a larger number of captured satellites is connected to the GPS receiving circuit 7.
In particular, when making a determination based on the number of captured satellites, if the number of captured satellites in the initial state, that is, the number of captured satellites of the sub-antenna 2B is greater than or equal to a predetermined number, the antenna switching control is not performed, It is desirable to perform antenna switching only when the number is less than the predetermined number. This method is more preferable because it may not be necessary to switch antennas more than necessary, and the control speed and processing load can be reduced, compared with the case where the number of acquired satellites is confirmed by switching antennas once. When a portable terminal is normally held by hand, a GPS antenna is not disposed at a position hidden by hand, and therefore, the number of captured satellites often satisfies the above-mentioned predetermined number or more in a place where the view is good to some extent. For this reason, the method of determining the presence or absence of antenna switching according to the comparison result using the predetermined number is effective and has a large effect.

Hereinafter, timing control of processing performed in the wireless communication terminal 1 before and after diversity will be described. In FIGS. 4 to 7, time slots are used for convenience of explanation. However, when there is no concept of time slots as in the CDMA communication method, the same processing can be performed by using the same processing timing. .
In the present invention, GPS reception after diversity may be performed at the same timing as before diversity, or may be performed at different timing.

FIG. 4 is a diagram illustrating processing when GPS reception is performed at different timings using time slots. 4A shows before diversity, that is, before antenna switching (initial state), and FIG. 4B shows after diversity (after antenna switching). FIG. 4C shows another example of processing in pass 1.
Before the diversity in FIG. 4A, the slot groups after the time T0 of the path 1 are indicated by the symbols “Sa1, Sb1,..., Sd1,. “Sa2, Sb2,..., Sd2,..., Sg2, Sh2,. Also, after the diversity in FIG. 4B, the slot group after the time T0 of the path 1 is indicated by reference signs “SA1,..., SC1, SD1,..., SF1,. A slot group after the time T0 is indicated by symbols “SA2,..., SC2,..., SF2,.
In FIG. 4, for the sake of convenience, the processing content is set for each slot having the same time width so that the start timing of each processing is matched. However, even in a communication method that does not have the concept of a time slot like the CDMA communication method, What is necessary is just to control so that the start timing of each process may be united.

Before the diversity shown in FIG. 4 (A), the control is the same as the control of the Simultaneous method of FIG. 3 (C) already described, and the GPS receiving circuit 7 is connected to the sub-antenna 2B.
If there is an instruction for antenna switching operation (diversity) between time T0 and time T1 in FIG. 4B, the antenna that the switching means 4 in FIG. Is switched from the sub-antenna 2B to the main antenna 2A. For this reason, the GPS reception processing function is changed to the path 1 side, and thereafter, the GPS reception processing is not performed in the path 2.
In this example, the timing at which the next GPS is started in path 1 is determined independently of the GPS reception timing before diversity in FIG. Therefore, GPS reception is executed on the path 1 side at a timing different from the timing indicated by the arrow 20 (slot SD1), that is, at the slot SC1 one slot before. In the GPS reception period (slot SC1), the path 2 cannot share data because the local related circuit 65B of FIG. 1 is shared (slot SC2).

Here, in the slot SC1 in FIG. 4B, the signal received via the main antenna 2A is demultiplexed into the frequency band signal of the terrestrial radio signal and the frequency band signal of the GPS signal by the demultiplexer 3a1. The frequency band signal of the terrestrial radio signal is input to the CDMA receiving circuit 6A via the demultiplexer 3a2, and the frequency band signal of the GPS signal is input to the GPS receiving circuit 7, whereby the CDMA reception in FIG. Data reception and GPS reception are performed in parallel using the circuit 6A and the GPS reception circuit 7.
Thereafter, GPS reception is repeated at a rate of once every three slots (slots SF1, SI1,...). For this reason, as indicated by an arrow 21, the GPS reception timing may be shifted before and after diversity. For other slots, server data transmission / reception (Server Tx / Rx) is performed at the same timing (time T3) before and after diversity (slot SH1), and data reception is performed in the remaining slots. In this way, by performing server data transmission / reception (Server Tx / Rx) after GPS reception at the same timing before and after diversity, the processing timing on the server side can be made the same. It is possible to suppress an increase in the load.
At this time, in the path 2, the slots SF2, SI2,... Corresponding to the GPS reception timing in the path 1 are in a dormant state, and the slot SH2 corresponding to the server data transmission / reception timing is also in the dormant state here. However, the latter dormant state is arbitrary and may be data reception.

FIG. 4C shows a modification example of the time T2 to T4 in FIG.
In this modified example, data reception is not performed in the GPS reception slot SF1 of path 1 and only GPS reception is performed.

Next, a process when the diversity is returned to the original initial state again will be described.
FIG. 5A and FIG. 5B are time slot diagrams after diversity is restored. These drawings show the period from time T2 to time T4 in FIG. 4A, and this processing is the same for other slots.
FIG. 5A shows a case where the processing is completely restored to the original state. In the path 1 while the GPS receiving circuit 7 is again connected to the sub-antenna 2B by diversity and GPS is received in the path 2, the slots Sd1 and Sg1 Receive data at. On the other hand, in FIG. 5B, the slots Sd1 and Sg1 of the path 1 are in a dormant state. For example, the processing shown in FIG. 5A may be performed when the amount of data to be received is large, and the processing shown in FIG. 5B may be performed when the amount of data to be received is small.

Next, an example in which slot reorganization is performed after diversity will be described.
FIG. 6 shows a time slot diagram in that case. Here, FIG. 6A and FIG. 6B are shown for reference with the same figure as FIG. 4A and FIG. 4B, and FIG. 6B is a slot diagram after diversity ( Part 1).
FIG. 6C shows a time slot diagram after diversity (part 2) when slot reorganization is performed. Server data transmission / reception (Server Tx / Rx) is executed in the slot SG1 immediately after the slot SF1 that performs GPS reception in the path 1.

The reason for slot reorganization in this way will be described next.
As shown in slot SF1 of FIG. 6B, GPS reception is performed at a timing different from that before diversity. At this time, if the slot timing of server data transmission / reception (Server Tx / Rx) is the same as that before diversity, GPS reception to server If there is a slot interval before data transmission / reception and the wireless communication terminal 1 moves during that time, an error occurs between the detection result obtained via the server and the current position. In order to minimize the error, it is necessary to perform server data transmission / reception immediately after GPS reception, as in FIG.
In this example, server data transmission / reception is reorganized to the next slot of GPS reception in response to this request. As a result, high detection accuracy can be maintained even after diversity.

In FIGS. 4 to 6, the GPS reception timing is controlled independently before and after diversity.
In contrast, FIG. 7 shows a time slot diagram when GPS reception is synchronized before and after diversity. FIG. 7A shows before diversity, and FIG. 7B shows after diversity.
As in FIG. 4B, there is an antenna switching command between times T0 and T1, and diversity is executed. In this example, in the time slot after diversity, GPS reception on path 1 starts at the same time T2 as the GPS reception timing before diversity. For this reason, GPS reception processing is synchronized before and after diversity in all GPS reception slots. Therefore, reorganization of server data transmission / reception (Server Tx / Rx) as shown in FIG. 6 is also unnecessary.
As in FIGS. 4 and 5, it is arbitrary whether GPS reception and data reception after diversity are performed in parallel or only by GPS reception.

In the description so far, the same time slot length (processing time length) is used, and the number of slots (time length) in one cycle shown in FIGS. 4, 6 and 7 is also the same.
In practice, however, the time for receiving data often varies depending on the data and sometimes. In addition, the GPS reception time and server data transmission / reception time fluctuate due to the influence of the reception environment, ease of connection (network complexity), and the like.

FIG. 8 shows a time slot diagram in such a case. 8A is before diversity, FIG. 8B is after diversity (part 1: when GPS reception is asynchronous (independent)), and FIG. 8C is after diversity (part 2: GPS reception is synchronized). If present).
As shown in path 2 in FIG. 8A, a GPS reception start time width T is determined in advance, and GPS reception is repeated in that cycle. It is assumed that the GPS reception period does not exceed this time width T. Data reception is possible during that time, but the time length and start timing of the data reception are arbitrarily set. There may also be a free time between data reception slots.
The arbitraryness of this data reception is the same in path 1 as well.

The control after diversity in FIG. 8B is when GPS reception is asynchronous before and after diversity. In this example, GPS reception is started on path 1 immediately after GPS reception on path 2 ends. . Also in this case, the GPS reception of the same time width T is periodically repeated starting from the first GPS reception. In this case as well, the data reception slot has arbitrary timing, length (time width), and number.
The control after diversity in FIG. 8C is a case where GPS reception is synchronized before and after diversity. The GPS reception timing before diversity in FIG. 8A and the GPS reception timing in FIG. Are almost identical in time. Data reception is performed at the timing and time width possible under the restriction.
In FIGS. 8B and 8C, GPS reception and data reception are executed in parallel in path 1 after diversity. However, data reception may not be performed during GPS reception. Further, since the configuration of FIG. 1 is assumed, while the GPS reception is performed on the path 1, the path 2 is in a data reception pause state. As described above, data can be received through path 2 during server data transmission / reception (Server Tx / Rx) through path 1 (not shown).

Furthermore, the ratio of the frequency of GPS reception and data reception can be made constant. For example, if GPS reception is performed for one slot, it is ruled that data reception is performed for two slots before the next GPS reception, and the ratio of the number of GPS reception and data reception slots is set to 1: 2. Is possible.
The control in the above example is shown in the flowchart of FIG. This control is executed by the control / processing circuit 8 of FIG. 1 (this is the same as the control of FIGS. 4 to 8), and the slot detection means used for this control is provided in the control / processing circuit 8, For example, a packet header of a radio signal (or GPS signal) determined by the CDMA communication standard (or GPS standard) is detected, and a packet group associated in advance is detected as a slot. A slot counter is also provided in the control / processing circuit 8. Here, it is assumed that the number of satellites is detected. A GPS counter that holds the number of times of actual GPS reception after detecting the number of satellites and determining the GPS reception path is also provided in the control / processing circuit 8.

In step ST1 of FIG. 9, the satellite signal from the sub-antenna 2B on the path 2 side is received by the GPS receiving circuit 7 in FIG. 1 in the initial state before antenna switching, and the number of satellites is detected in the control / processing circuit 8 I do. The detected number of satellites α is compared with a predetermined value A determined in advance in the control / processing circuit 8, and if α <A, it is determined that antenna switching is necessary, and the switching means 4 in FIG. Give instructions and switch antennas. On the other hand, if α <A, it is determined that antenna switching is not necessary, and the processing that has been performed is continued (details omitted).
Thereafter, the slot detection means in the control / processing circuit 8 successively detects the beginning or end of the slot (step ST2).
On the other hand, the control / processing circuit 8 detects the number of satellites β captured by the antenna after diversity (main antenna 2A) in an appropriate slot after step ST1 (step ST3). In step ST3, the control / processing circuit 8 determines that the GPS reception is performed by the main antenna 2A on the path 1 side on the condition that the number of satellites β is larger than the number of satellites α before diversity. Notify the switching means 4.
Further, the control / processing circuit 8 sets the initial value of the GPS counter value J to J = 2, which is one less than J = 3 (step ST4), and sets the initial value of the slot counter value K to K = 2 (step ST4). ST5).

After this counter value is set, the data reception of path 1 accompanied with the counter count is performed. That is, referring to FIG. 4, the processing of steps ST1 to ST5 is performed from time T0 to time T2, and the next slot SD1 is counted as a slot after formal antenna switching. Until then, the counter counting before antenna switching is continued. The reason why J = 2 is set in step ST4 is that GPS reception is already executed once immediately after antenna switching as shown in FIG.
When the slot detecting means of the control / processing circuit 8 detects the first slot in the data receiving step of step ST6, the slot counter value K is decremented to K-1 (= 1) in the next step ST7. Steps ST6 and ST7 are repeated until it is determined in the next step ST8 that K = 0.
In the control shown in FIG. 9, the control using the time slot has been described. However, when the concept of the time slot is not used, the control may be performed similarly using the same timing, time length, and the like.

If it is determined in step ST8 that K = 0, the GPS reception circuit 7 performs GPS reception under the control of the control / processing circuit 8 in the next step ST9 (corresponding to the slot SF1 in FIG. 4).
When the GPS reception ends, the control / processing circuit 8 decrements the GPS counter value J in the next step ST10. The control / processing circuit 8 and the GPS receiving circuit 7 repeat the processing from the above steps ST5 to ST11 until J = 0 is determined in the next step ST11. During this time, simple position detection correction by the control / processing circuit 8 is executed for each GPS reception.

If J = 0 is determined in step ST11, the control / processing circuit 8 determines that server data transmission / reception (Server Tx / Rx) is necessary.
In response to this determination, the process of the next step ST12 is executed. In this process, first, the control / processing circuit 8 transmits the data acquired from the satellite signal to the server via the transmission circuit 5 of FIG. After that, position calculation is performed by the server, and when the calculation result is input to the control / processing circuit 8 via the main antenna 2A and the CDMA receiving circuit 6A, accurate position detection is executed based on the calculation result.
Such position detection and simple position detection correction are appropriately reflected in the current position display of the map data by data reception, and the user is notified of the current position.
In step ST13, the control / processing circuit 8 constantly monitors the end of communication, and the process ends when the end is detected. On the other hand, if not finished, the control / processing circuit 8 sets the GPS counter value to the initial value J = 3 in step ST14, and repeats the processing after step ST5 until it is judged to be finished in step ST13.
In the control shown in FIG. 9, the control using the time slot has been described. However, when the concept of the time slot is not used, the control may be performed similarly using the same timing, time length, and the like.

The wireless communication terminal 1 and the wireless communication system including the wireless communication terminal 1 and the base station according to the present embodiment have the following advantages and features.
As shown in FIG. 1, the wireless communication terminal 1 of the present embodiment is connected to a CDMA receiving circuit 6A connected to a first antenna (main antenna 2A) and a second antenna (sub antenna 2B). Since the CDMA receiving circuit 6B and the GPS receiving circuit 7 are provided and the antenna connected to the GPS receiving circuit 7 can be switched by the switching means 4 operated by the control of the control / processing circuit 8, the above-described diagram. 4 to 9, both the satellite signal and the radio signal (data signal) are received when the GPS receiving circuit 7 is connected to the main antenna 2A and the sub-antenna 2B. Is possible. Further, since the local related circuit 65B is shared by the CDMA receiving circuit 6B and the GPS receiving circuit 7, the circuit area and cost can be saved accordingly.

In addition, an algorithm for diversity GPS reception processing using a so-called "Simultaneous" method has been newly proposed. This algorithm has the following characteristics.
(1) First feature: When switching the antenna for performing GPS reception processing, for example, when detecting the number of satellites and / or when it is decided to switch the antenna for performing GPS reception processing, GPS reception is originally performed. GPS reception is performed at a timing periodically different from the GPS reception start timing (GPS reception timing when connected to the sub-antenna 2B in the initial state).
(2) Second feature: normal data reception using the first antenna and GPS reception performed using the first antenna when switching from GPS reception using the second antenna to GPS reception using the first antenna Are performed at the same timing. Alternatively, data reception is not performed when GPS reception is performed at this timing.
(3) All of the following timings of the GPS reception timing after switching (in terms of time) or slots at specific intervals are set as “transmission of data including GPS data to server (base station) / GPS data. The processing configuration is reorganized (changed) so as to be assigned to an operation such as “receiving data from a server (base station)”.
(4) The GPS reception for diversity reception switching detection and / or the GPS reception cycle timing (time slot timing) after switching are matched with the cycle timing performed using the original antenna. Alternatively, the GPS reception start timing is allocated independently before and after diversity. Therefore, the GPS reception start timing may be the same or different.

Since the wireless communication terminal or the wireless communication system of the present embodiment has the above characteristics, it has the following advantages.
(1) Since the two antennas are compatible with GPS, the risk that position measurement is impossible due to shielding by hands or the like is reduced. Also, diversity reception compatible with high-speed data communication can be realized with a single GPS receiver.
(2) Since GPS reception can be performed at an independent timing different from the original GPS reception cycle (timing), for example, when it is determined that GPS reception is severe with one antenna, without waiting until the next GPS reception timing GPS reception (detection) becomes possible at the next timing with the other antenna. For this reason, it is possible to immediately execute the diversity reception operation in accordance with the change in the radio wave reception state. In addition, since the GPS reception timing can be determined without being limited by the current GPS reception cycle even after antenna switching, high-speed data communication is possible while maintaining positioning accuracy.
(3) When normal data reception and GPS data reception are performed at the same timing, GPS positioning accuracy can be maintained while maintaining high-speed data communication. On the other hand, when normal data reception and GPS data reception are performed at different timings, it is possible to cope with a case where the amount of received data is small.
(4) Even if the GPS reception start timing changes due to diversity reception, the positioning accuracy can be maintained by exchanging with the base station at the next timing after GPS reception. In other words, even if it becomes impossible to perform positioning using only satellite data, it is possible to switch to a mode that uses base station data, etc. at any time. Services can be provided.
(5) When processing organization is performed, since the GPS reception timing is the same before and after diversity reception, slot adjustments such as “take a slot for communication with the base station after the GPS reception slot” become unnecessary. .

It is a block diagram of the radio | wireless communication apparatus which concerns on embodiment of this invention. (A) And (B) is explanatory drawing of the antenna arrangement | positioning and shielding of a radio | wireless communication terminal. (A)-(D) are the time slot diagrams of the GPS reception system in diversity reception. (A)-(C) are time slot diagrams in the case of performing GPS reception at different timings. (A) and (B) are time slot diagrams after the diversity is restored. (A)-(C) are time slot diagrams in the case where slot reorganization is performed after diversity. (A) and (B) are time slot diagrams when GPS reception is synchronized before and after diversity. (A)-(C) is a figure which shows time slot length according to actuality. It is a flowchart of slot control.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Wireless communication terminal, 2A ... Main antenna, 2B ... Sub antenna, 3a1, 3a2, 3b ... Demultiplexing circuit, 4 ... Switching means, 5 ... Transmission circuit, 6A, 6B ... CDMA receiving circuit, 7 ... GPS receiving circuit, 8 ... Control and processing circuit

Claims (7)

A first antenna and a second antenna;
A first receiving circuit that is not connected to the second antenna but is connected to the first antenna and that receives a radio signal received by the first antenna; and
A second receiving circuit that is not connected to the first antenna but is connected to the second antenna and receives a radio signal received by the second antenna;
Switching means for switching connection to either one of the first antenna and the second antenna;
A satellite reception circuit that performs reception processing of the satellite signal received by either one of the first antenna and the second antenna connected via the switching unit;
Signal processing means for performing signal processing by inputting a signal processed by at least one of the first receiving circuit and the second receiving circuit;
Satellite signal processing means for inputting a satellite signal processed by the satellite receiving circuit and performing signal processing;
A wireless communication apparatus comprising: First demultiplexing means for demultiplexing a signal received by the first antenna is provided between the first antenna and the switching means,
The wireless communication according to claim 1, wherein second demultiplexing means for demultiplexing a signal received by the second antenna is provided between the second antenna and the switching means. apparatus. Provided with a reference signal output means capable of outputting a plurality of reference signals,
It said second receiver circuit includes a first mixing means to mix and one reference signal and the second antenna is output from the wireless signal and the reference signal output means has received,
The satellite receiving circuit according to claim 1 or 2, characterized in that it comprises a second mixing means to mix the other one of the reference signal outputted from said satellite signal and the reference signal output circuit Wireless communication device. When the satellite reception circuit is connected to the first antenna via the switching unit, the satellite reception circuit receives the satellite signal regardless of the reception processing of the radio signal in the first reception circuit. The wireless communication apparatus according to claim 3. The satellite signal processing means sets the reception start timing of the satellite signal from the satellite to the same timing as before the switching when the antenna connected to the satellite receiving circuit is switched by the switching means. The radio | wireless communication apparatus of any one of Claims 1-4. When the antenna connected to the satellite reception circuit is switched by the switching unit, the satellite signal processing unit controls the reception start timing of the satellite signal from the satellite independently from before switching. The radio | wireless communication apparatus of any one of Claims 1-4. The wireless communication apparatus according to any one of claims 1 to 6,
A transmission circuit for transmitting data acquired in the reception process of the satellite reception circuit to a base station;
When the antenna connected to the satellite reception circuit is switched by the switching means, the transmission control means for controlling the transmission start timing of the data from the transmission circuit,
A wireless communication system, further comprising: a base station comprising position information calculation means for receiving the data transmitted by the transmission circuit and calculating position information based on the data.

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