CN106612125B

CN106612125B - Apparatus and method for receiving broadcast

Info

Publication number: CN106612125B
Application number: CN201510691355.4A
Authority: CN
Inventors: 刘彤浩
Original assignee: Microsoft Technology Licensing LLC
Current assignee: Microsoft Technology Licensing LLC
Priority date: 2015-10-22
Filing date: 2015-10-22
Publication date: 2020-09-25
Anticipated expiration: 2035-10-22
Also published as: CN106612125A

Abstract

An apparatus for receiving a broadcast is provided. In one embodiment, the apparatus includes a plurality of antennas for receiving broadcast signals; a signal evaluation unit configured to evaluate a quality of the received broadcast signal; a phase tuning unit coupled to at least one of the antennas and configured to adjust a phase difference between the plurality of antennas; and a control unit configured to control the phase tuning unit for improving the quality. The device allows a user to use an existing wire such as an earphone to serve as an antenna for a portable multifunction device, and improves the performance of broadcasting by tuning a phase difference between wires. A method of receiving a broadcast and a portable multifunction device are also provided.

Description

Apparatus and method for receiving broadcast

Background

Conventionally, people are able to receive radio waves using devices such as radios or mobile phones in order to listen to audio or watch video broadcast programs on such devices. It is common for such devices to utilize a retractable antenna so that the user can manually adjust the orientation and length of the antenna himself, thereby enabling reception of broadcast signals with a higher signal-to-noise ratio (SNR). If the SNR can reach higher levels, it generally means that the quality of the radio content can be improved. Because the transmitter is typically located away from a particular receiver, the antenna receives the enhanced signal by pointing in one direction, although the antenna also receives the attenuated signal by pointing in some other direction.

More and more content is conveyed in the high frequency band, such as Frequency Modulated (FM) signals ranging from 65 to 108MHz and Digital Television (DTV) signals ranging from 400 to 800 MHz. Since the demand for antenna length is inversely proportional to the increase in frequency, the size of an antenna for receiving FM or DTV signals is much smaller than an antenna for receiving Amplitude Modulated (AM) signals. Thus, antennas for modern mobile devices can have their antennas integrated within or as part of the housing. However, existing devices do not allow the user to adjust the direction or length of the antenna, making performance difficult to improve.

Disclosure of Invention

According to an embodiment of the subject matter described herein, there is provided an apparatus for receiving a broadcast. The apparatus includes a plurality of antennas for receiving a broadcast signal, a signal evaluation unit configured to evaluate a quality of the broadcast signal, and a phase tuning unit coupled to at least one of the antennas. The device further comprises a control unit configured to control the phase tuning unit in order to improve the quality. By using at least two antennas, the phase difference between the antennas can be deliberately adjusted to test whether the quality or SNR of the received signal is enhanced or weakened during the adjustment of the phase difference. The phase setting may then be set to one that maximizes signal quality. By adjusting the phase difference, the electrical characteristics are adjusted as if the equivalent length of the antenna were also changed. In this way the performance of the antenna is controllable. A corresponding method and a portable multifunctional device comprising the device are also described.

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify pipe features or core features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

Drawings

Figure 1 illustrates a schematic diagram of an apparatus for receiving a broadcast according to an embodiment of the subject matter described herein;

figure 2 illustrates a schematic diagram of an apparatus for receiving a broadcast according to another embodiment of the subject matter described herein;

figure 3 illustrates a schematic diagram of an apparatus for receiving a broadcast according to another embodiment of the subject matter described herein;

figure 4 illustrates experimental results of sensitivity as a function of frequency if signals are received at different antenna configurations; and

fig. 5 illustrates a flow chart of a method of receiving a broadcast according to various embodiments of the subject matter described herein.

Detailed Description

The subject matter described herein will now be discussed with reference to several exemplary embodiments. These examples are discussed only for the purpose of enabling those skilled in the art to better understand the subject matter described herein and are not intended to limit the scope of the subject matter in any way.

The term "comprising" and its variants are to be regarded as open-ended terms, which means "including but not limited to". The term "or" should be considered "and/or" unless the context clearly dictates otherwise. The term "based on" shall be considered to be "based at least in part on". The terms "one embodiment" and "an embodiment" should be considered "at least one embodiment". The term "another embodiment" shall be taken to be "at least one other embodiment". Unless specified or limited otherwise, the terms "mounted," "connected," "supported," and "coupled" and variations thereof are used broadly and encompass both direct and indirect mountings, connections, supports, and couplings. Further, "connected" and "coupled" are not restricted to physical or mechanical connections or couplings. In the following description, like reference numerals and labels are used to describe the same, similar or corresponding parts in the several views of fig. 1-5. Other explicit and implicit definitions are included below.

The antenna is used to receive radio waves and such signals carrying visual and/or audible information are then processed by the device in order to be played. FM broadcasting has been widely used for decades and it communicates audio signals over radio waves having a frequency band ranging from 65 to 108MHz in most parts of the world. DTV broadcasting operates in a manner similar to FM broadcasting, but with a frequency band falling within a range from about 400 to 800 MHz. FM and DTV broadcasts are a flat solution for mobile devices because the user does not need to pay for the data stream charges charged by the operator. However, the quality of the received broadcast signal depends on several factors, such as location (distance from the receiver to the transmitter), orientation, and other antenna characteristics. In many cases, the signal strength received by the device is not satisfactory and the quality of the resulting reproduced FM or DTV content is compromised.

A phased array is an array of antennas in which the relative phases of the respective signals input to the antennas are set in such a way that the effective radiation pattern of the array is emphasized in the desired direction and suppressed in the undesired direction. With antennas utilizing phased arrays, the strength of the received signal can be intentionally adjusted by the antenna. As a result, the performance of broadcast reception can be improved in principle.

For mobile phones it is possible to arrange a module within the phone for receiving broadcast signals via the headset. The headset has a wire connected to the transducer at one end and to a plug at the other end. The wire may include a plurality of wires encased within an insulating tube. For example, the wires include a first wire for carrying a left channel signal, a second wire for carrying a right channel signal, a third wire for carrying a microphone channel signal, and a fourth wire as a reference ground. The wire acts as an antenna and directs the broadcast signal into the module in response to the plug being connected to the headset hole on the mobile phone.

If the headset is used as an antenna for a mobile device, the strength of the signal is typically weak, especially for DTV signals. Existing devices do not provide an effective solution to this weakness.

Fig. 1 illustrates a schematic diagram of an apparatus 100 for receiving a broadcast according to an embodiment of the subject matter described herein. The device 100 is described for illustrative purposes only and is not intended to limit the scope of the subject matter described herein in any way. Different embodiments having different structures may achieve the objects and concepts of the subject matter described herein.

As shown, the device 100 includes a plurality of antennas 110 for receiving broadcast signals. As shown, the phase tuning unit 130 is coupled in series with one of the antennas 110. However, more than one phase tuning unit 110 is also possible. In one embodiment, each antenna 110 includes a phase tuning unit 130. A signal evaluation unit 120 is provided to evaluate the quality of the received broadcast signal. Example metrics for quality include, but are not limited to, SNR. I.e. a higher SNR value means a better quality and vice versa. Alternatively, or additionally, the spectrum of the signal may be used as a measure of signal quality. In the following discussion, SNR will be described as an example, and thus in decibels (dB) will be used to indicate how much improvement is.

In the case shown in fig. 1, three antennas 110 are provided. Thus, there are multiple possible antenna combinations (single or multiple). For example, only one of the antennas 110 may be used (enabled), allowing three combining possibilities. When some of the antennas 110 are used or enabled, the remaining antennas 110 are disabled, meaning the remaining antennas 110 are disconnected. Two of the antennas 110 may be used (enabled), thus allowing three other possibilities for combination. Finally, all of the antennas 110 are used, which adds an additional possibility. In summary, if all three antennas are used (enabled) in the device 100, there are seven possible combinations. Similarly, if four antennas are used, there are 15 combinations of possibilities (4+6+4+ 1).

The quality of the received signal changes for each possibility. Because different combinations of antennas 110 change the directivity or orientation of the overall antenna, the quality will vary greatly between different combinations. In other words, sometimes only one antenna 110 is sufficient to achieve the best SNR, and sometimes all antennas 110 can bring the best SNR.

In one embodiment, the signal evaluation unit 120 measures the quality of the received signal in real time and the combinations of antennas 110 are all tested until one of the combinations yields the best quality. This combination may be referred to as an optimal combination. This process may occur when the device 100 is turned on, and may also occur in real time during operation, as the antenna is not typically fixed in space.

The device 100 comprises a control unit 140 coupled to the signal evaluation unit 120 and to the phase tuning unit 130. Based on the output of the signal evaluation unit 120, the control unit 140 controls the phase tuning unit 130 for improving the quality of the received broadcast signal. For example, the control unit 140 may control the phase tuning unit 130 such that one of the antennas 110 coupled to the phase tuning unit 130 makes a change in phase difference with the other antennas.

In one embodiment, the control unit 140 controls the phase tuning unit 130 and the latter changes the phase difference in both directions. In other words, in general, a phase difference that changes in one direction may improve the quality evaluated by the signal evaluation unit 120, while a phase difference that changes in the other direction impairs the quality. Naturally, an improved quality is advantageous and the control unit 140 can find the maximum quality by various known optimization algorithms.

The phase tuning unit 130 may exist in various forms. For example, the phase tuning unit 130 may be a combination of voltage controllable capacitors and other components. The capacitance variable diode may be coupled to one of the antennas 110 at one end and grounded at the other end. If a different DC voltage is applied, the value of the capacitance will be changed such that the phase difference between the particular antenna and the remaining antennas is changed accordingly. In some embodiments, an integrated chip may be provided for varying the phase difference of one antenna from the remaining antennas. Such means of achieving phase tuning are known and will not be explained in detail.

Because the signal evaluation unit 120 is used to evaluate whether the quality of the signal received as a whole is acceptable or has improved by a certain degree, the signal evaluation unit 120, the control unit 140 and the phase tuning unit 130 together can form a control loop such as a negative feedback loop. By adjusting the phase tuning unit 130 over time based on the evaluated results, the quality of the signal will be gradually improved, and such a control process may be implemented by the control unit 140 using existing algorithms, such as Random or Robust (Robust) or Genetic (Genetic) algorithms.

The top line of the device 100 may change at any time as the user uses the device 100. Thus, in one embodiment, the signal evaluation unit 120 remains operative to monitor whether the quality has significantly dropped by a predefined threshold. If the predefined threshold is dropped, the respective combinations of antennas are evaluated again accordingly (as described above), thereby assigning the combination that allows the best quality or the best combination. And in one embodiment, the signal evaluation unit 120 keeps scanning the SNR for various combinations. If the SNR of a scan is higher than the current SNR, a new configuration corresponding to the higher SNR is used to replace the current configuration. Therefore, the system is always dynamic to obtain the best SNR.

Figure 2 illustrates a schematic diagram of an apparatus for receiving a broadcast according to another embodiment of the subject matter described herein. In this embodiment, the signal evaluation unit 120, the control unit 140, the antenna 110 and the phase tuning unit 130 are similar to the embodiment illustrated by fig. 1, and thus a detailed explanation thereof will not be made.

In this example, four phase tuning units 130 are provided, and each phase tuning unit 130 is coupled to a corresponding antenna 110. Furthermore, a control unit 140 is coupled to all phase tuning units 130 in order to assume full control over the antenna 110. In this way, adaptive control of the phase tuning unit 130 based on the result evaluated by the signal evaluation unit 120 can be used to maintain the quality at a relatively high level.

A frequency filtering unit 150 may be provided between the antennas and the signal evaluation unit 120 in order to filter the received signals carried by all antennas 110. For use such as FM broadcast, the frequency filtering unit 150 may include a low pass filter such that frequency signals above a certain value (e.g., 108MHz) will be substantially attenuated by the filter. Likewise, for uses such as DTV broadcasting, the frequency filtering unit 150 may include a high-pass filter such that frequency signals below a certain value (e.g., 400MHz) will be substantially attenuated by the filter. In one embodiment, the FM signal and the DTV signal may be processed separately.

In one embodiment, the apparatus 100 may comprise a memory 160 configured to store a configuration corresponding to the optimal combination and phase difference by which the quality allows the SNR to exceed a predefined threshold. Because a user may only use the device in a limited number of locations that the user often visits, it would be useful to quickly invoke a previously saved configuration that corresponds to the user's current location. As a result, the phase tuning process as described above can be significantly shortened.

In some embodiments, the device 100 may also include a navigation unit 170 coupled with the memory 160. The navigation unit 170 is configured to detect location data of the device 100 and is implemented, for example, as a Global Positioning System (GPS) receiver. For example, when the user is at home, he/she may take some time for the device 100 to find the optimal combination and phase difference between the antennas 110. The user may then save the configuration relative to the current settings of the antenna in combination and phase tuning. When the user is at home on another day, he/she may simply invoke the saved configuration corresponding to home. Through the navigation unit 170, the control unit 140 may be able to determine whether the current location coincides with one of the previously saved configurations. In this way, the control unit 140 automatically initializes the setting of the antenna, possibly allowing a rapid enhancement in quality.

Figure 3 illustrates a schematic diagram of an apparatus for receiving a broadcast according to another embodiment of the subject matter described herein. In this embodiment, the signal evaluation unit 220, the control unit 240, the frequency filtering unit 250, the memory 270, the navigation unit 280, and the phase tuning unit 230 are similar to the embodiment illustrated by fig. 2, and thus a detailed explanation thereof will not be made.

Device 200 may be a portable multifunction device such as a smart phone. The portable multifunction device 200 includes a broadcast processing unit 210 that is similar in function to the device 100 for receiving broadcasts shown by fig. 2. The earphone 260 has a wire detachably connected to the broadcast processing unit 210 via the phase tuning unit 230. The wire may include a plurality of wires 262 encased within an insulating tube. Typically, the wires include a first wire for carrying a left channel signal, a second wire for carrying a right channel signal, a third wire for carrying a microphone channel signal, and a fourth wire that is a reference ground. Thus, four wires are shown in fig. 3 for illustrating a typical headset. In response to the plug being connected to the earphone hole on the mobile phone, for example, the wire serves as an antenna and guides the broadcast signal into the frequency filtering unit 250.

The solution of using a headset as an antenna is advantageous because the mobile device is always provided with a headset so that the user does not need to purchase additional antenna components. While some existing mobile phones have been able to receive broadcast content via headphones, the solution according to embodiments of the herein described subject matter successfully improves the SNR of the signal received by the control loop formed by the signal evaluation unit, the control unit and the phase tuning unit(s).

Fig. 4 shows experimental results of the sensitivity as a function of frequency if signals are received under different antenna configurations. These tests are conducted in a frequency range for DTV, i.e., from about 400MHz to about 800 MHz. Each configuration uses multiple antennas with different phase tuning. In this case, a headphone including a left channel, a right channel, a microphone channel, and a reference channel is used as an antenna. It can be seen that the SNR varies by more than 10dB over the entire frequency range. These tests were performed by using fixed capacitors for different phase tuning. Thus, since phase tuning can be implemented with higher accuracy and in a controllable manner, the practical results can be further improved by using a phase tuning unit according to the subject matter described herein.

Referring to fig. 5, a block diagram of a method 500 of receiving a broadcast is illustrated according to various embodiments of the subject matter described herein. The method 500 is entered at step 501 where a broadcast signal is received by a plurality of antennas.

In step 502, the quality of the received broadcast signal is evaluated. In step 503, the phase difference between the antennas is controlled for improving quality.

In one embodiment, the quality may include a signal-to-noise ratio of the broadcast signal.

In a further embodiment, the method may further comprise, before controlling the phase difference between the antennas: a combination of the plurality of antennas is determined based on the quality.

In yet another embodiment, the method may further include filtering the received broadcast signal for passing broadcast signals within a plurality of frequency ranges.

Additionally or alternatively, the plurality of frequency ranges includes a first range for Frequency Modulated (FM) signals and a second range for Digital Television (DTV) signals.

In a further embodiment, the method may further comprise storing a configuration corresponding to the determined combination and the phase difference, and controlling the phase difference is based on the configuration.

In yet another embodiment, the method may further comprise detecting a location; storing a location associated with the stored configuration; and in response to the detected location matching the stored location, controlling a phase difference between the antennas by applying to the stored configuration corresponding to the stored location.

Although operations are depicted in the above description in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In some cases, multitasking or parallel processing may be advantageous. Likewise, although the above discussion contains certain details, this should not be construed as limiting the scope of the subject matter described herein, but rather as descriptions of features that may be directed to particular embodiments. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. In other instances, features which are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination.

Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. An apparatus (100) comprising:

a plurality of antennas (110) for receiving broadcast signals;

a signal evaluation unit (120) configured to evaluate the quality of the received broadcast signal;

a phase tuning unit (130) coupled with at least one of the antennas and configured to adjust phase differences between the plurality of antennas; and

a control unit (140) configured to control the phase tuning unit for improving the quality,

wherein the signal evaluation unit is further configured to measure a plurality of broadcast signals received from a plurality of combinations of the antennas in response to the received broadcast signal falling by a predefined threshold; and

the control unit is further configured to determine a combination of the plurality of antennas that provides the best quality of the broadcast signal among the plurality of combinations of antennas.

2. The apparatus of claim 1, wherein the control unit is configured to control the phase tuning unit for improving the quality over time, the quality comprising a signal-to-noise ratio (SNR) of the broadcast signal.

3. The apparatus of claim 1, wherein the phase tuning unit is coupled with each of the antennas.

4. The apparatus of claim 1, wherein the control unit is configured to enable the determined combination of the antennas prior to the control of the phase tuning unit.

5. The device of claim 1, further comprising a frequency filtering unit (150) coupled with the plurality of antennas and configured to pass the broadcast signals within a plurality of frequency ranges.

6. The apparatus of claim 5, wherein the plurality of frequency ranges comprises a first range for Frequency Modulated (FM) signals and a second range for Digital Television (DTV) signals.

7. The device of claim 1, further comprising a memory (160) configured to store a configuration corresponding to the determined combination and the phase difference, the control unit further configured to control the phase tuning unit based on the configuration.

8. The apparatus of claim 7, further comprising:

a navigation unit (170) configured to detect a location of the device;

wherein the memory is further configured to store a place associated with the stored configuration, and

wherein the control unit is further configured to control the phase difference between the antennas by applying the stored configuration corresponding to the stored location in response to the location detected by the navigation unit matching the stored location.

9. A method of receiving a broadcast, comprising:

receiving a broadcast signal through a plurality of antennas;

evaluating the quality of the received broadcast signal;

controlling phase differences between the plurality of antennas for improving the quality;

measuring a plurality of broadcast signals received from a plurality of combinations of the antennas in response to the received broadcast signal falling by a predefined threshold; and

determining a combination of the plurality of antennas that provides the best quality of the broadcast signal among the plurality of combinations of antennas.

10. The method of claim 9, wherein the quality comprises a signal-to-noise ratio (SNR) of the broadcast signal.

11. The method of claim 9, further comprising:

filtering the received broadcast signal for passing the broadcast signal within a plurality of frequency ranges.

12. The method of claim 11, wherein the plurality of frequency ranges comprises a first range for Frequency Modulated (FM) signals and a second range for Digital Television (DTV) signals.

13. The method of claim 9, further comprising:

storing a configuration corresponding to the determined combination and the phase difference, and controlling the phase difference is based on the configuration.

14. The method of claim 13, further comprising:

detecting a location;

storing a location associated with the stored configuration; and

in response to the detected location matching the stored location, controlling the phase difference between the antennas by applying the stored configuration corresponding to the stored location.

15. A portable multifunction device (200), comprising:

a broadcast processing unit (210); and

a headset (260) detachably connected to the broadcast processing unit, wherein a wire (262) of the headset serves as an antenna for receiving broadcast signals when connected to the broadcast processing unit,

the broadcast processing unit includes:

a signal evaluation unit (220) configured to evaluate the quality of the received broadcast signal;

a phase tuning unit (230) coupled with at least one of the wires in response to the earphone being connected to the broadcast processing unit and configured to adjust a phase difference between the wires; and

a control unit (240) configured to control the phase tuning unit for improving the quality;

16. The portable multifunction device of claim 15, wherein the phase tuning unit is coupled with four of the wires in response to the headset being connected to the broadcast processing unit.

17. The portable multifunction device of claim 15, further comprising a frequency filtering unit (250) coupled to the wire responsive to the earpiece being connected to the broadcast processing unit and configured to pass the broadcast signal within a frequency range of Frequency Modulation (FM) and digital television (DVT).