WO2005020509A1

WO2005020509A1 - Wireless communication system for electronic devices

Info

Publication number: WO2005020509A1
Application number: PCT/IB2004/051521
Authority: WO
Inventors: Achim Hilgers; Heiko Pelzer
Original assignee: Philips Intellectual Property & Standards Gmbh; Koninklijke Philips Electronics N. V.
Priority date: 2003-08-26
Filing date: 2004-08-23
Publication date: 2005-03-03

Abstract

The invention relates to a communication system for wireless communication between electronic devices (5, 6, 7, 8, 9, 10, 11, 12). The system comprises a communication base station (13) and a plurality of communication units which are each assigned to an electronic device (5, 6, 7, 8, 9, 10, 11, 12), in which the communication base station (13) and the communication units have antenna modules for setting up radio links (17, 18, 19, 20, 21) both between the communication base station (13) and the communication units and also among the communication units themselves. To optimize the efficiency of such a communication system the invention proposes that at least one of the antenna modules comprises a variable radiation pattern.

Description

Wireless communication system for electronic devices

The invention relates to a communication system for wireless communication between electronic devices, comprising a communication base station and a plurality of communication units which are each assigned to an electronic device, the communication base station and the communication units having an antenna module for setting up radio connections both between the communication base station and the communication units and also among the communication units themselves. Both in the in-home environment and in the office environment wireless networking of a wide variety of electronic devices is becoming ever more normal. In-home devices that can be networked include on the one hand personal computers inclusive of corresponding peripheral devices. On the other hand, the network also includes the devices of entertainment electronics available in most households such as, for example, television sets, stereo systems, video recorders, DVD players and DVD recorders etc. On account of the advance in the range of multimedia technology, particularly the connection between PC and said devices of entertainment electronics via well-suited data networks becomes ever more important. Preferably, for networking said devices, wireless communication links are used. Cable links in the household area are rather unsuitable because the necessary network cabling is not provided in the electrical installation in most homes. So-called power line networks, in which the data transmission takes place via the power supply lines, have not been proceeded with. In addition, the cable-bound networking is disadvantageous seeing the increasing number of mobile devices used in home and office environments such as, for example, laptops, PCs, personal digital assistants (PDAs), wireless telephones, digital cameras, camcorders etc. Nowadays already there are powerful technologies available for wireless data exchange via radio links between a great variety of devices. To mention a few are the what is known as Bluetooth technology or wireless local area network (WLAN) technologies, for example, in accordance with the 802.11 standard. Furthermore, the MIMO technology (multiple in multiple out) become known of late may be pointed to in this respect. The data transmission with sufficient transmission bandwidth for most multimedia applications is possible via corresponding wireless networks. The in-home electronic devices mentioned above are increasingly capable of processing digital multimedia data such as, for example, MP3, MPEG, DV or HTML. Therefore, it is advantageously possible now already to give these devices access to the reproducible and recordable multimedia data by means of Bluetooth or WLAN technology. With the known wirelessly operating communication systems for the networking of domestic electronic devices, communication units with antenna modules are assigned to the individual devices, which units serve the purpose of establishing the necessary radio connections between the devices. These communication units may be integrated, for example, with a plug-in board for a desktop or laptop PC, but also be arranged as set top boxes for various devices of entertainment electronics, as integrated components Already when particularly mobile electronic devices are manufactured, communication units with associated antenna modules used for wireless networking are increasingly used.

From US 2002/0021465 Al is known a communication system which can be used for wireless communication between home electronic devices. In the known communication system discussed above there is a communication base station which particularly forms the interface between the networked home electronic devices and an external telecommunication network (Internet). The communication base station sets up data links to the communication units of the known communication system. The devices networked in this manner can then access external data contents via the Internet. The communication base station then serves as a gateway to the external data network. In addition, the communication base station in the known system has the object to ensure the interoperability of the various electronic devices in the home. The communication base station is then in a position to automatically recognize the available devices, configure them and control the data exchange between the communication base station and the communication units on the one hand and also among the communication units themselves. The communication base station in the known system monitors the data volume arising during the data transmission, and more particularly parts of the available transmission bandwidth are reserved for certain multimedia applications as required. The latter functionalities of the communication base station are assigned to the what is called quality of service (QoS) range. Safeguarding the QoS is particularly important for the transmission of multimedia data such as, for example, video data so that, on playback of a digital video transmitted between individual communication units, always the desired picture quality is achieved. Furthermore, in the known communication system the communication base station gives priorities for the data transmission between the individual communication units so as to avoid an overload of the wireless data network as a result of an instantaneously too high data load. In the known communication system the functionality of the communication base station to guarantee the QoS reaches limits when the maximum data transmission bandwidth is exhausted in all available frequency bands. This may be the case relatively fast if for example only little-compressed video data of high quality are to be transmitted. In such a case the wireless network of the known communication system is blocked for the data transmission between communication units which do no take part in the transmission of the video data. In the known system the wireless data transmissions disadvantageously form each other's interference since the respective radio signals are always received by all the communication units of the system.

Starting from this, it is an object of the present invention to provide a system for wireless communication between electronic devices which system is optimized with respect to the data transmission rate that can be achieved. More particularly, the possibility of guaranteeing the QoS for the data transmission in an in-home communication network is to be improved relative to the state of the art. This object is achieved by the invention based on a communication system of the type defined in the opening paragraph in that at least one of the antenna modules has a variable directional radio pattern. In accordance with the invention at least several of the antenna modules of the communication system are structured such that they have a variable directional radio pattern and thus a directional radio pattern that can be adapted to the instantaneous situation of data transmission. With the communication system according to the invention there is the advantageous possibility of setting the radio characteristics of the individual antenna modules so that only small confined spaces, for example of the home in which the communication system is installed, are radiated by radio signals. The radiation is then efficiently concentrated on these rooms in which there are electronic devices to which a data transmission is to take place. This immediately offers the advantage that further devices of the in-house communication network are not disturbed and that a simultaneous and independent data transmission between these devices can take place with a maximum bandwidth. This clearly increases the overall possible data transmission rate against the known systems. Accordingly, the advantage of the communication system according to the invention can particularly be noticed in that, depending on the situation of data transmission, frequency ranges can be used multiple times. Furthermore, as a result of the limitation of the radiation of radio signals to several rooms in the home automatically leads to an increase of the signal level in these rooms as compared to conventional wireless communication systems in which the radiation is effected isotropically. Compared to conventional systems, this leads to reduced susceptibility to errors during the data transmission and also to an increase of the maximum possible distance between the electronic devices which is possible for error-free data transmission. A further advantage of the system according to the invention consists of the fact that the room is not homogeneously radiated by radio signals, as is customary in known systems, but only in such limited room areas that are involved in the respective data transmission. According to patent claim 2 at least one of the antenna modules of the communication system according to the invention which module has a variable directional radio pattern comprises two or more antennas which are spatially apart. To drive these antennas, in accordance with patent claim 3 a phase control module should then efficiently be provided for influencing the antennas with transmitted signals of different phases and for phase-shifting received signals. The transmitted signals emitted by the antennas which are spatially apart are each other's interference with different room areas being radiated depending on the phase of the transmitted signals. As a result of the phase shift of the transmitted signals the radio pattern is adapted according to the invention to the respective data transmission situation. For this purpose is used the phase control module which is structured in known manner. In addition to the pre-definition of the phases of the transmitted signals, the phase control module can advantageously also be used for phase shifting the received signals so as to maximize the receiving level. More particularly, the spatial position of the respective transmitting antenna module can be determined by means of the phase control module in that the receive level is maximized while the respective phase values are determined simultaneously. The radio pattern of the antenna modules of the communication system according to the invention can thus be adapted also automatically to the respective spatial positions of the electronic devices communicating with each other, which is highly advantageous with respect to mobile devices which, by nature, may be located at the most different positions in the home or in the office. For the communication system according to the invention are particularly suitable single and multiband antennas as are known from for example EP 1 289 053 A2. Multiband antennas are advantageous in that a plurality of frequency bands are available for data transmission, which is advantageous to the bandwidth of the wireless communication network. Suitable phase control also makes possible for a single antenna module to transmit in different frequency ranges with different radiation patterns. In this way a single communication unit of the communication system according to the invention can, for example, simultaneously exchange data with the communication base station and with one or more other communication units and all with maximum data rates. Furthermore, in accordance with patent claim 4 a high-frequency module and a digital control module may be provided for connecting the antennas to the communication base station or to one of the communication units. The high-frequency module is used for converting received radio signals into digital signals. These digital signals are applied to the digital control module to drive the respective electronic devices. Conversely, the digital control module represents the data interface for digital data which are to be transmitted from the respective electronic device to another device. The digital control module in the transmit mode drives the high-frequency module which converts the respective data signals into high- frequency signals. According to patent claim 5 the communication base station and/or the communication units have an electronic control which can control the radio pattern of the respective antenna module such that the emission of transmitted signals in the direction of several of the electronic devices takes place in accordance with their spatial positions. For this purpose, the respective communication base station or the respective communication unit should know the position of the electronic device to which the data are to be sent. Efficaciously, in accordance with patent claim 6, the communication base station can comprise a data memory for this purpose, in which the spatial positions of the in-home electronic devices are stored. In the simplest case the spatial positions of at least the stationary in-home electronic devices may be directly entered in the data memory of the communication base station of the system according to the invention. However, as described above, there is also the possibility of determining the spatial positions of the individual devices automatically. According to patent claim 7 the radiation pattern of the antenna module of a communication unit of the communication system according to the invention can be directly controlled by means of the electronic control of the communication base station, that is to say in accordance with the respective device's spatial position stored in the data memory of the communication base station. To control the radiation pattern, the respective control signals are efficaciously also transmitted via a radio link to the communication unit concerned. According to patent claim 8 the communication base station of the communication system according to the invention may advantageously be used as an interface to an external communication network, for example, to the Internet. It is then advantageous for the communication units to make contact with the communication base station in a purpose-oriented way while using the variable radiation pattern of their antenna module, without the communication between other communication units of the wireless data network being affected as a result of the data traffic created. The basic idea of the invention consists after all of the fact that an antenna module, which has a variable directional radio pattern, is used for establishing wireless network links by radio between electronic devices. Based on the known Bluetooth, WLAN or MIMO systems this basic idea can be materialized in that instead of the usual isotropically radiating antenna modules of the communication units assigned to the individual electronic devices, antenna modules can be used having two or more antennas which are spatially apart, while the antennas, as described above, are individually driven with different phases in accordance with the desired radiation direction.

For further clarification the invention described above will be further explained in the following by means of examples of embodiment while reference is made to the drawing Figures in which: Fig. 1 gives a diagrammatic representation of the use of a communication system according to the invention in a common home; Fig. 2 shows an antenna module for use in accordance with the invention.

Fig. 1 shows a customary home in the form of a ground plan. The home comprises a bedroom 1, a kitchen 2, a living room 3 as well as a bathroom 4. Inside the home there are a number of in-home electronic devices. In the bedroom 1 there is a television set 5. In the kitchen 2 there are a refrigerator 6, a microwave oven 7 and a radio set 8. In the living room 3 there is a further television set 9 with a DVD player 10 connected to it and furthermore a PC 11. The bathroom 4 accommodates again a radio 12 as a single device. The electronic devices present in the home shown communicate with each other in a wireless fashion by means of the communication system according to the invention. This system comprises a communication base station 13, which represents the interface to an external telecommunication network 14 (Internet) via an analog, ISDN or DSL telephone line. To the electronic devices 5, 6, 7, 8, 9, 10, 11 and 12 shown are assigned communication units not further shown, while the communication base station 13 and said communication units in Fig. 1 also have antenna modules (not shown) for setting up radio links. A typical situation of data transmission is diagrammatically shown in Fig. 1. A resident 15 of the house has a cordless telephone 16 in his hand. The telephone link to a communication partner connected to the external communication network 14 is then set up via a radio link 17 between telephone 16 and communication base station 13. There is a further radio link 18 between the PC 11 and the television set 9. Via this radio link 18 a video data stream is transmitted from the hard drive of the PC 11 to the television set 9, which plays back the respective video. Via a bidirectional radio link 19 between the refrigerator 6 and the communication base station 13 the intelligent electronic control of the refrigerator 6 simultaneously carries out an on-line order of groceries on the Internet via the external communication network 14. The antenna modules of the individual communication units according to the invention each have a variable directional radio pattern which is shown in Fig. 1 in that the radio links are confined each to ranges spatially limited by the dotted lines. The communication units of the electronic devices 5, 6, 7, 8, 9, 10, 11 and 12 each have an electronic control by which the radiation pattern can be controlled, so that the radiation of the transmitted signals in the direction of the respective electronic devices or the communication base station 13 respectively, is effected in accordance with their spatial positions. For this purpose the spatial positions of the refrigerator 6, the microwave oven 7, the television set 9, the PC 11 etc. are stored in a special data memory of the communication base station 13. The radio direction for a radio link 21 between the microwave oven 7 and the telephone 16 is controlled via a radio link 20 between the communication base station 13 and the microwave oven 7. The resident 15 of the house then receives via the radio link 21 the message from the microwave oven 7 that the cooking time for the preparation of a meal has ended. As can be clearly seen from Fig. 1 there is no overlap whatsoever between the room areas which are covered by the radio links 17, 19, 20 and 21 with the spatial range determined by the radio link 18. For this reason the transmission of the video data from the PC 11 to the television set 9, which transmission requires a large bandwidth, is not disturbed by the other existing radio links 17, 19, 20 and 21. The playback of the video by the television set 9 can therefore be effected with optimum picture quality. The antenna module shown as a block diagram in Fig. 2 has four antennas 22 which are spatially apart to realize the variable directional radio pattern according to the invention. A phase control module 23 is provided for driving the antennas 22, which module can be used to send transmit signals of different phases selectively to the antennas 22. Furthermore, the phase control module 23 is used for superpositioning in the right phase the receive signals received by the antennas 22 so as to maximize thereby the overall level of the received signal. To the phase control module 23 is connected a high-frequency module 24 which converts received high-frequency signals into digital signals and conveys them to a digital control module 25. The digital control module 25 represents the interface to an electronic device not further shown in Fig. 2, which device is provided with the antenna module for the purpose of wireless communication within the communication system according to the invention. Data signals to be transmitted over the wireless radio link are applied to the high-frequency module 24 by the digital control module 25, while the high- frequency module 24 converts these digital signals into respective high-frequency signals.

Claims

CLAIMS:

1. A communication system for wireless communication between electronic devices (5, 6, 7, 8, 9, 10, 11, 12), comprising a communication base station (13) and a plurality of communication units which are each assigned to an electronic device (5, 6, 7, 8, 9, 10, 11, 12), the communication base station (13) and the communication units having an antenna module for setting up radio connections (17, 18, 19, 20, 21)both between the communication base station (13) and the communication units and also among the communication units themselves and in which at least one of the antenna modules has a variable directional radio pattern.

2. A communication system as claimed in claim 1, in which at least one of the antenna modules having a variable directional radio pattern comprises two or more antennas (22) which are spatially apart.

3. A communication system as claimed in claim 2, in which for driving the antennas (22) a phase control module (23) is provided for sending transmit signals of different phases to the antennas (22) and for phase shifting the phases of received signals.

4. A communication system as claimed in claim 3, in which a high-frequency module (24) and a digital control module (25) are provided in addition to the connection of the antennas (22) to the communication base station (13) or to one of the communication units.

5. A communication system as claimed in any one of the claims 1 to 4, in which the communication base station (13) and/or the communication units have each an electronic control by which the directional radio pattern can be controlled such that the radiation of transmitted signals in the direction of several of the electronic devices (5, 6, 7, 8, 9, 10, 11, 12) takes place in accordance with their spatial positions.

6. A communication system as claimed in claim 5, in which the communication base station (13) comprises a data memory in which the spatial positions of the electronic devices (5, 6, 7, 8, 9, 10, 11, 12) can be stored.

7. A communication system as claimed in claim 6, in which the radiation pattern of the antenna module of one communication unit can be controlled by means of the electronic control of the communication base station (13) via a radio link to at least this communication unit in accordance with the stored spatial positions of the electronic devices (5, 6, 7, 8, 9, 10, 11, 12).

8. A communication system as claimed in any one of the claims 1 to 7, in which the communication base station (13) is connected to an external communication network (14).

9. Use of an antenna module having a variable directional radio pattern with two or more antennas (22) for establishing a wireless communication link (17, 18, 19, 20, 21) by radio communication between electronic devices (5, 6, 7, 8, 9, 10, 11, 12).