CN101167266A - Radio apparatus - Google Patents

Abstract

The radio device (400) comprises first and second antennas (42, 44), a first transceiver (40) having a first transmitter (60) and a first receiver (61), a second receiver (62), switching means (45, 46) arranged to provide selectable first and second states, and control means (50) adapted to select between the first and second states for simultaneous transmission and reception by the first transmitter (60) and the second receiver (62). The switching means (45, 46) enable coupling the first transmitter (60) to either of the first and second antennas (42, 44) while coupling the second receiver (62) to the other of the first and second antennas (42, 44), but prohibit coupling the first transmitter (60) and the second receiver (62) to the same antenna (42 or 44).

Description

radio equipment

technical field

The invention relates to radio equipment incorporating antenna diversity.

Background technique

It is well known that antenna diversity is a method for improving communication quality in systems in which radio signals undergo multipath propagation. Some configurations of antenna diversity provide selection between multiple antennas for transmission or reception, other configurations provide combining of signals received via multiple antennas. The latter configuration requires a more complex receiver capable of combining the signals. The former configuration, called antenna selection diversity, requires a simpler receiver and is most relevant to the present invention.

An example of a radio device using antenna selection diversity is shown in FIG. 1 . It includes a transceiver (Tx/Rx) 10 coupled to a selector switch 16 . A selector switch 16 can be controlled to couple either of the two antennas 12 , 13 to the transceiver 10 . An antenna can thus be selected for both transmission and reception. A controller (not shown) controls selector switch 16, the selection being based on received signal quality.

It is also known that radio equipment is equipped to operate on more than one signal type, for example equipped to transmit and receive not only mobile phone signals for communication with the mobile phone network, but also for communication with Bluetooth enabled Mobile phones that communicate with Bluetooth signals from cell phones or personal computers, and mobile phones that are also equipped to receive Global Positioning System (GPS) signals. Other combinations are conceivable, for example a mobile phone also equipped to receive television signals. Such devices are referred to in this specification as "dual-signal devices" and are characterized by the ability to simultaneously transmit and receive different signals carrying different data bits. The term "dual-signal device" is not intended to exclude the possibility that the device is adapted to transmit and receive more than two signals simultaneously.

Figure 2 shows an example of a dual signal device. The dual signal device comprises two transceivers 10,11, each coupled to a respective antenna 12,13. One of the transceivers may be replaced by a receiver, eg as required to receive broadcast signals from broadcast systems that do not require return transmissions. As shown in FIG. 2, a dual-signal device may include at least one antenna for each receiver or transceiver to provide isolation between different signals that are simultaneously transmitted and received. It is possible for the two transceivers 10,11 to use a common antenna, but in this case filters need to be incorporated to ensure proper isolation between the two transceivers 10,11. Such filters are undesirable because they would increase passband loss and reduce transmitter efficiency while increasing component count and cost.

In order to improve the communication quality of a dual-signal device, the antenna diversity shown in FIG. 1 can be applied to the device shown in FIG. 2 . FIG. 3 shows the resulting device structure, the same reference numerals being assigned to the same elements as in FIG. 3 and FIG. 1 or 2 . In order to provide antenna diversity for the two transceivers 10 , 11 , four antennas 12 , 13 , 14 , 15 are provided and a dual selector switch 18 comprising two selector switches 16 is required. A controller for controlling these switches is not shown, but each selector switch 16 will be controlled independently, since the multipath propagation experienced by each signal is generally independent. The device shown in Figure 3 has the disadvantage of requiring four antennas, which increases the size of the device.

Contents of the invention

It is an object of the present invention to provide improved radio equipment suitable for dual signal operation incorporating antenna diversity.

According to the present invention there is provided radio equipment comprising:

first and second antennas;

a first transceiver, including a first transmitter and a first receiver;

second receiver;

switching means arranged to provide selectable first and second states, wherein in the first state the output of the first transmitter is coupled to the first antenna and not coupled to the second antenna, and the input of the second receiver coupled to the second antenna and not coupled to the first antenna; and

coupling the output of the first transmitter to the second antenna and not to the first antenna and coupling the input of the second receiver to the first antenna and not to the second antenna in the second state; and

Control means adapted to select between first and second states for simultaneous transmission by the first transmitter and reception by the second receiver.

This device is used to ensure that simultaneous transmission and reception of different signals takes place via different antennas. The present invention provides a dual-signal device that incorporates antenna diversity but requires fewer antennas than the device shown in Figure 3, thus enabling a more compact device and simplifying the need for isolation between the transmitter and receiver. need. To benefit from these advantages, the device cannot independently select antennas for simultaneous transmission and reception of different signals. However, in environments such as an arbitrary choice of antenna for a signal is more likely to result in an acceptable signal level than an unacceptable signal level (which is expected to be the case in most locations within the coverage area of the radio system) , such restrictions are acceptable.

In one embodiment, the apparatus is adapted to couple the first and second receivers to different ones of the first and second antennas when the first and second receivers receive simultaneously. Such an embodiment has the advantage of being easy to implement.

In another embodiment, the apparatus is adapted to couple either of the first and second receivers independently to either of the first or second antennas when the first and second receivers receive simultaneously. Such an embodiment has the advantage of providing independent receive diversity for both receivers.

The selection of the state by the control means may depend on the indication of signal quality. A variety of optional different signal quality criteria are available for antenna selection. For example, via either or both of the first and second antennas, it may be possible to generate An indication of signal quality. In this way, the device can perform a selection that optimizes its own reception quality.

The selection of the state by the control means may be responsive to the value of a signal received via at least one of the first and second antennas. In this way, the device can perform a selection to optimize reception by an external device that receives the signal emitted by the device and sends the device a command to change state or an evaluation of the signal quality measured by the external device. instruct.

Combinations of the above status selection criteria can be used.

Description of drawings

The invention will be described, by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 is the functional block diagram of prior art antenna diversity equipment;

Fig. 2 is a functional block diagram of prior art dual-signal equipment;

Fig. 3 is a functional block diagram of a dual-signal device with antenna diversity;

Figure 4 is a functional block diagram of a device according to the invention;

Figure 5 is a flowchart of a method of operating the apparatus of Figure 4; and

Fig. 6 is a functional block diagram of another device according to the present invention.

Detailed ways

4, there is shown a first embodiment of a radio device 400 according to the present invention, comprising a first antenna 42, a second antenna 44, a first transceiver 40 comprising a first transmitter 60 and a first receiver 61, and second receiver 62 . For example the first transceiver 40 may be a mobile telephone transceiver for communication with GSM (Global System for Mobile Communications) or UMTS (Universal Mobile Telecommunications System) or other mobile telephone networks. The second receiver 62 is adapted to receive a different signal carrying different data bits than the first receiver 61 . For example, the second receiver 62 may be a broadcast receiver for receiving digital television signals such as DVB (Digital Video Broadcasting) or in particular DVB-H (Digital Video Broadcasting-Handheld) signals or any other broadcast signal.

There are switching means 45 , 46 comprising antenna selector means 46 and routing means 45 . The antenna selector means 46 operates as a changeover switch, arranged to couple either of the antennas 42 or 44 to the first transceiver 40 and the other of the antennas 42 or 44 to the second receiver 62 through the routing means 45 . If the first transceiver 40 is suitable for half-duplex operation, that is, it can (but not simultaneously) transmit or receive signals, then the routing means 45 can be used to connect the first transmitter 60 and the first receiver Either of 61 is coupled to the switch of the antenna selector means. Half-duplex operation may be used in Time Division Multiple Access (TDMA) systems, where transmission and reception need not occur simultaneously, even though operation may give the user the impression of full-duplex operation. Alternatively, routing means 45 may be duplex if first transceiver 40 is adapted for full-duplex operation (i.e. can transmit and receive signals simultaneously), or even if first transceiver 40 is adapted for half-duplex operation device.

The switching means 45, 46 provide a first state (in which the output of the first transmitter 60 is coupled to the first antenna 42 and not to the second antenna 44, and the input of the second receiver 62 is coupled to the second antenna 44). two antennas 44 and not coupled to the first antenna 42) and a second state (in which the output of the first antenna 60 is coupled to the second antenna 44 and not coupled to the first antenna 42, the second receiver The input of 62 is coupled to the first antenna 42 and not coupled to the second antenna 44. The state selection of the switching means 45, 46 is controlled by the control means 50 such as a microcontroller. When it is necessary to carry out the transmission of the first transmitter 60 and the second Upon reception by the second receiver 62, the control means 50 are adapted to select one of the first and second states.

Optionally, there are signal quality measuring means 52 , 53 coupled to the control means 50 for measuring a quality parameter of at least one of the signal received by the first receiver 61 and the signal received by the second receiver 62 . The quality parameter may be one or more: signal level, signal-to-noise ratio, signal-to-interference ratio, bit error rate, frame error rate or any other parameter representing signal quality. The control means 50 select the state of the switching means 45, 46 depending on the value of the measured quality parameter.

Alternatively, or in addition, the device 400 may receive a signal from an external device comprising a command or an indication of the quality of the signal transmitted by the device 400 and received by the external device, and implement the command or indication to select the switching means 45, 46 states. For example, the external device may report when the signal received by the external device from device 400 is below a predetermined quality threshold for a predetermined duration.

Referring to Figure 5, an example of a method of selecting the state of the switching means 45, 46 is shown. By way of example, consider the first transceiver 40 to be a GSM transceiver and the second receiver 62 to be a DVB receiver. The method starts at step 100 in which an initial state of the switching means 45 , 46 and thus an antenna for each of the first transceiver 40 and the second receiver 62 is arbitrarily selected.

Flow enters step 110 where a test is performed to determine whether the device is currently required to operate as a GSM phone and/or DVB receiver based on the user needs indicated by the user interface means. If the device is required to operate only as a GSM phone, flow proceeds to step 120 where a signal quality measurement is made on the received GSM signal by signal quality measurement means 52, such as a received signal strength indicator (RSSI) circuit, and tested to determine whether the measured value exceeds a predetermined value T _GSM . If the measured value exceeds the predetermined value T _GSM , flow returns to step 110 . Keeping the current state of the switching device, the test at step 110 is repeated in a loop to detect when the user indicates a need to receive DVB signals.

If the test at step 120 indicates that the measured value does not exceed the predetermined value T _GSM , flow proceeds to step 130 where the antennas are swapped so that the other antenna is now coupled to the first transceiver 40 . The same test as step 120 is then performed at step 140 to determine whether the GSM signal now being received by the other antenna meets the quality criteria. If the measured value exceeds the predetermined value T _GSM , the flow returns to step 110 .

If the test at step 140 indicates that the measured value does not exceed the predetermined value T _GSM , then this indicates that neither antenna 42 or 44 is receiving a GSM signal of sufficient quality to exceed the quality threshold requirement T _GSM , so at step 150 it is selected to receive a more An antenna for a good quality GSM signal is used for the first transceiver 40 . Flow then returns to step 110 .

If at step 110 the device is required to operate only as a DVB receiver, flow proceeds to step 160 where a signal quality measurement is made on the received DVB signal by signal quality measurement means 53, such as a received signal strength indicator (RSSI) circuit , and a test is performed to determine if the measured value exceeds a predetermined value T _DVB . If the measured value exceeds the predetermined value T _DVB , flow returns to step 110 . Keeping the current state of the switching device, the test at step 110 is repeated in a cyclical fashion to detect when the user indicates the need to receive GSM signals.

If the test at step 160 indicates that the measured value does not exceed the predetermined value T _DVB , flow proceeds to step 170 where the antennas are swapped so that the other antenna is now coupled to the second receiver 62 . The same test as step 160 is then performed at step 180 to determine whether the DVB signal currently being received by the second receiver 62 meets the quality criteria. If the measured value exceeds the predetermined value T _DVB , flow returns to step 110 .

If the test at step 180 indicates that the measured value does not exceed the predetermined value T _DVB , then this indicates that neither antenna 42 or 44 is receiving a DVB signal of sufficient quality to exceed the quality threshold requirement T _DVB , so at step 190 it is selected to receive a more An antenna for a good quality DVB signal is used for the second receiver 62 . Flow then returns to step 110 .

Other antenna selection criteria may be used. For example, when the device is required to operate in only one mode (such as a GSM mobile phone or a DVB receiver), the control means 50 are operable to select the antenna 42 or 44 which provides a higher quality signal rather than the antenna which provides a higher quality signal. Signals exceeding a suitable quality threshold T _GSM or T _DVB .

If the test indication at step 110 requires the device to operate as a GSM mobile phone and a DVB receiver at the same time, the flow enters steps 160 to 190, where the decision about which antenna to couple to the second receiver 62 is based on the The selection criteria for DVB signals are met; the first transceiver 40 is coupled to the antenna 42 or 44 not used by the second receiver 62 .

Alternatively, if the test at step 110 indicates that the device needs to operate as a GSM mobile phone and a DVB receiver at the same time, the flow may proceed to steps 120 to 150, where the decision on which antenna to couple to the first transceiver 40 is based on The reception criteria for GSM signals are met at steps 120 and 140 ; the second receiver 62 is coupled to the antenna 42 or 44 not used by the first transceiver 40 .

Alternatively, the selection criteria may take into account the quality of the received GSM signal and the received DVB signal if the testing at step 110 indicates that the device is required to operate simultaneously as a GSM mobile phone and a DVB receiver. For example, such a scheme could be used to ensure, where possible, that GSM signals and DVB signals are received at a level above a suitable quality threshold, ie T _GSM or T _DVB .

Alternatively or additionally, the selection criterion may take into account the value of the signal received by either of the first and second receivers 61, 62 as described above. In this way, the device can perform selections to optimize reception by an external device that receives signals transmitted by the device and sends commands to the device to change state or to send an indication of signal quality measured by the external device.

Referring to Figure 4, as mentioned above, the control means 50 are adapted to select one of the first and second states when simultaneous transmission by the first transmitter 60 and reception by the second receiver 62 is required. If it is required that the device 400 simultaneously receives different signals through the first receiver 61 and the second receiver 62 according to the requirements of the system on which the device 400 operates, or according to user requirements, then optionally, the control device 50 may be adapted to select One of the third and fourth states. In the third state, the input of the first receiver 61 is coupled to the first antenna 42 and not to the second antenna 44, and the input of the second receiver 62 is coupled to the second antenna 44 and not to the first antenna 42. In the fourth state, the input of the first receiver 62 is coupled to the second antenna 44 but not to the first antenna 42, and the input of the second receiver 62 is coupled to the first antenna 42 but not to the second antenna 44. The control means 50 are adapted to select between the third and fourth states for simultaneous reception by the first and second receivers 61 , 62 using one or more of the aforementioned selection criteria.

If the first transceiver 40 switches back and forth between transmitting and receiving (i.e. half-duplex operation), the control means 50 will cause the device 400 to be in one of the first and second states and one of the third and fourth states. switch between. Typically, but not exclusively, reception by the first receiver 61 and transmission by the first transmitter 60 may occur most of the time via a common antenna, although the particular choice of antenna will vary as propagation conditions vary. This corresponds to using states one and three and states two and four most of the time. Optionally, reselection of states may occur at transitions between transmit and receive.

If the first transceiver 40 operates both the transmission of the first transmitter 60 and the reception of the first receiver 61 (i.e. full-duplex operation), the device 400 as described with reference to FIG. 4 will operate in states one and three simultaneously Alternatively operating in states two and four simultaneously, the control means 50 will control the selection of these pairs based on one or more of the above selection criteria.

Referring to Figure 6, a second embodiment of a radio device 500 according to the present invention is shown. Except for the differences described below, the elements of the second embodiment are the same as those of the first embodiment described above with reference to FIG. 4 and bear the same reference numerals. The differences are:

(i) The antenna selector arrangement 46 of FIG. 6 is used as a pair of selector switches 48 configured to enable the first transceiver 40 and the second receiver 62 to be each independently coupled to either of the antennas 42, 44. , including coupling to the same or different antennas 42,44.

(ii) The switching means 45, 46 in the second embodiment provide the first, second, third and fourth states described above in relation to the first embodiment, and additionally provide the fifth and sixth states. In the fifth state, the input of the first receiver 61 and the input of the second receiver 62 are coupled to the first antenna 42 and not to the second antenna 44 . In the sixth state, the input of the first receiver 61 and the input of the second receiver 62 are coupled to the second antenna 44 and not to the first antenna 42 . The control means is adapted to use one or more of the above selection criteria to select one of the first and second states when simultaneous transmission by the first transmitter 60 and reception by the second receiver 62 is desired, and when the first state is desired One of the third, fourth, fifth or sixth states is selected for simultaneous reception with the second receiver 61,62.

(iii) if the first transceiver 40 is capable of full-duplex operation (i.e. simultaneous transmission by the first transmitter 60 and reception by the first receiver 61), then assuming that the configuration to the selected two states is met, one can One of the third, fourth, fifth or sixth states and one of the first and second states are selected simultaneously. For example, selection of the first and third states simultaneously couples the first transmitter 60 and the first receiver 61 to the first antenna 42 and couples the second receiver 62 to the second antenna 44 . As another example, selection of the first and sixth states simultaneously couples the first transmitter 60 to the first antenna 42 and couples the first and second receivers 61 , 62 to the second antenna 44 . Transmission and reception by the first transceiver 40 can thus occur simultaneously via different antennas. An example where a combination of states cannot be achieved due to conflicting states is the simultaneous combination of states 1 and 5.

The embodiment of FIG. 6 may operate according to the method described above with reference to FIG. 5, or variations of the method may use additional fifth and sixth states.

At least one of the first and second receivers 61, 62 may be adapted to receive signals divided into time frames, eg GSM signals or DVB-H signals. In this case, when such a signal is being received, the control means 50 may be adapted to reselect the state of the switching means 45, 46 only at time frame boundaries, so that the received signal is not corrupted by the reselection.

The first transceiver 40 may be adapted to alternately transmit and receive in a time-division mode, and may include time periods in which neither transmission nor reception occurs, during which power savings may be achieved. Similarly, the second receiver 62 may be adapted to alternate periods of reception and periods of time when no reception occurs, thus achieving power savings during periods of no reception. The control means (50) may be adapted to reselect the state of the switching devices 45, 46 only when one or more of the following conditions are met: the first transmitter 60 is not transmitting; the first receiver 61 is not receiving; the second receiving Machine 62 is not receiving.

Optionally, the device 400 or 500 may include a second transceiver including a second receiver 62 and a second transmitter. In this case, the control means 50 and the switching means 45, 46 may also be adapted to ensure that the simultaneous transmission of the first transmitter 60 and the second transmitter takes place via different ones of the antennas 42, 44, thus avoiding the transmission via the common antenna 42 or 44, and may be adapted to ensure that simultaneous transmission and reception of the second transmitter and first receiver 61 occurs via different ones of the antennas 42, 44, thus avoiding the simultaneous transmission and reception of the second transmitter via the common antenna 42 or 44 Simultaneous transmission and reception with the first receiver 61.

The measurement means 52, 53 may be integral with the respective receiver 61, 62 or may be separate.

The switching means 45, 46 may be implemented using electronic or electromechanical technology.

Although the invention has been described with reference to the case of two antennas and two receivers and optionally two transmitters, the use of further antennas, receivers or transmitters is not excluded.

Although embodiments have been described with reference to GSM and DVB, the invention may also be used in connection with other wireless systems, such as Wireless Local Area Networks (WLAN) or Digital Audio Broadcasting (DAB).

Although example criteria for selecting a state of a device 400 or 500 have been described, the use of other selection criteria is not precluded.

In the present description and claims the term "a" or "an" preceding an element does not exclude the presence of several of such elements. Furthermore, the term "comprising" does not exclude the presence of other elements or steps than those listed.

Reference numerals included in parentheses in the claims are for facilitating understanding and not for limitation.

From reading this disclosure, other modifications will be apparent to those skilled in the art. Such modifications may introduce other features known in the field of radio communication and antenna diversity schemes, which may be used instead of or in addition to those already described herein.

Claims (9)

1. A radio apparatus comprising: first and second antennas (42, 44); a first transceiver (40), comprising a first transmitter (60) and a first receiver (61); a second receiver (62); switching means (45, 46) arranged to provide selectable first and second states, wherein, In the first state, the output of the first transmitter (60) is coupled to the first antenna (42) but not to the second antenna (44), and the second receiver The input of the machine (62) is coupled to the second antenna (44) and not coupled to the first antenna (42), and In the second state, the output of the first transmitter (60) is coupled to the second antenna (44) but not to the first antenna (42), and the second receiver The input of the engine (62) is coupled to the first antenna (42) and not coupled to the second antenna (44); and Control means (50) adapted to select between said first and second states for simultaneous transmission and reception by said first transmitter (60) and said second receiver (62). 2. The apparatus of claim 1, wherein, The switching means (45, 46) have selectable third and fourth states, wherein in the third state the input of the first receiver (61) is coupled to the first antenna (42 ) without coupling to the second antenna (44), and coupling the input of the second receiver (62) to the second antenna (44) without coupling to the first antenna (42), as well as In the fourth state, the input of the first receiver (62) is coupled to the second antenna (44) but not to the first antenna (42), and the second receiver The input of the engine (62) is coupled to the first antenna (42) and not coupled to the second antenna (44); and Said control means (50) is adapted to select between said third and fourth states for simultaneous reception by said first and second receivers (61, 62). 3. The apparatus of claim 2, wherein, The switching device (45, 46) has optional fifth and sixth states, wherein, In the fifth state, the input of the first receiver (61) and the input of the second receiver (62) are coupled to the first antenna (42) and not to the second Antenna (44), and In the sixth state, the input of the first receiver (61) and the input of the second receiver (62) are coupled to the second antenna (44) and not to the first Antenna (42); and Said control means (50) is adapted to select between said third, fourth, fifth and sixth states for simultaneous reception by said first and second receivers (61, 62). 4. Apparatus as claimed in claim 1, 2 or 3, comprising measuring means (52, 53) for measuring signals received by said first receiver (61) and said second receiver (62 ) of at least one quality parameter of the received signal to generate an indication of signal quality, wherein said control means (50) is adapted to select a state of said switching means based on said indication of signal quality. 5. Apparatus as claimed in claim 1, 2, 3 or 4, wherein said control means (50) is adapted to select the state of said switching means (45, 46) in response to the value of the received signal. 6. Apparatus according to any one of claims 1-5, wherein said control means (50) are adapted to reselect the state of said switching means (45, 46) only if one or more of the following conditions are met: The first transmitter 60 is not transmitting; the first receiver 61 is not receiving; the second receiver 62 is not receiving. 7. The device according to any one of claims 1-6, wherein said first transceiver (40) is adapted to operate on a mobile telephone network. 8. The device of any one of claims 1-7, wherein the second receiver (62) is adapted to receive broadcast signals. 9. The apparatus of claim 8, wherein the broadcast signal is a digital television signal or a digital audio signal.

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