MXPA99005463A - Wireless communications station and system - Google Patents

Abstract

A wireless communications station comprising a base unit including a communications interface for communicating with plural wireless communications networks, a received communications combiner for combining received communications signals received from the plural wireless communications networks into a single radio frequency output, a transmit communications splitter for splitting previously combined transmit communications signals to be transmitted to the plural wireless communications networks into plural radio frequency outputs, at least one fiberoptic transmitter receiving the single radio frequency output and providing a corresponding optical output, and at least one fiberoptic receiver receiving an optical input and providing an RF output containing previously combined transmit communications signals, a plurality of remote units, each including plural antennas for communicating with communicators along plural wireless communications networks, a received communications splitter for splitting previously combined received communicationssignals from the base unit and supplying them to the plural antennas, a transmit communications combiner for combining transmit communications signals from the plural antennas into a combined radio frequency output, a fiberoptic transmitter receiving the combined radio frequency output and providing a corresponding optical output, and a fiberoptic receiver receiving an optical input and providing an RF output to the received communications splitter containing previously received transmit communications signals, a first optical fiber connecting each fiberoptic transmitter of the base unit with a corresponding fiberoptic receiver in a corresponding remote unit, and a second optical fiber connecting each fiberoptic transmitter of a remote unit with a corresponding fiberoptic receiver in the base unit.

Description

STATION AND WIRELESS COMMUNICATIONS SYSTEM FIELD OF THE INVENTION The present invention relates to communication systems generally and more particularly to wireless communication systems employing optical fibers.

BACKGROUND OF THE INVENTION Cellular radio is conceived to provide high capacity mobile communications without requiring large amounts of spectrum. The original concept as proposed by AT & T, comprises the use of a frequency band within a region known as a cell and reuses the same frequency band in other adjacent cells with manageable interference between the cells.

The capacity of a cellular radio network increases as the number of cells increases with decreasing cell size. Small cells are known as microcells. The optical fibers have been used to feed the RF signal to the microcells. Fiber optic can be presented inside buildings, train stations, meshes, etc. for Ref. 030565 to improve coverage in a wireless communication system.

U.S. Patent 5,457,357 describes a number of details of a fiber-optic cellular radio system.

The current wireless communications systems can be divided into a number of groups. These include cell phone networks, cordless phones, wide area data networks, wireless urban area networks, people / message search networks and satellite mobile systems. Each wireless communication system has its own frequency band and modulation scheme, as well as its own geographic site, on which the system is deployed. Some of these systems may become obsolete, while others may develop into future personal communication systems. However, it seems that two or more wireless systems will be commonly found anywhere.

Conventionally, each wireless communication system has its own network for improved coverage in buildings and other shaded areas. A building which requires improved coverage for more than one wireless service must be "wired" separately for each service.

BRIEF DESCRIPTION OF THE INVENTION The present invention seeks to provide an improved distributed antenna array for microcells. The present invention further seeks to provide a single optical fiber network, which is used simultaneously for a number of wireless communication systems.

Accordingly, a wireless communication station is provided according to a preferred embodiment of the present invention comprising: a base unit that includes: a communication interface for communication with plural wireless communications networks; a communications combiner received to combine the received communications signals received from the plural wireless communications networks into a single radio frequency output; a transmission communication splitter for dividing the previously combined transmission communications signals that are transmitted to plural wireless communications networks into plural radiofrequency outputs, - at least one fribooptic transmitter that receives the unique radiofrequency output and provides an optical output correspondent; Y at least one fiber-optic receiver that receives an optical input and provides an RF output containing previously combined transmission communication signals; a plurality of units at a distance, each comprising: plural antennas for communicating with communicators along wireless communication networks; a communications splitter received for dividing the received communications signals previously combined from the base unit and supplying them to plural antennas; a transmission communications combiner for combining the transmission signals of the plural antennas into a combined radio frequency output; a fiber-optic transmitter that receives the combined radiofrequency output and provides a corresponding optical output; Y a fiber-optic receiver that receives an optical input and provides an RF output to the received communications splitter that contains the previously received transmission communications signals; a first optical fiber connecting each fiber-optic transmitter of the base unit with a corresponding fiber-optic receiver in a corresponding distance unit; Y a second optical fiber connecting each fiber-optic transmitter of a remote unit with a corresponding fiber-optic receiver in the base unit.

Preferably each remote unit also comprises a diplexer or other isolation apparatus interposed between each of the plural antennas and the combiner and the divider, to allow communications of two simultaneous routes via each antenna at different frequencies for transmission and reception .

Preferably the plural wireless communication networks include at least two communication networks selected from the group consisting of cellular telephone networks, cordless telephones, wide area data networks, wireless urban area networks, personal communication systems, networks of personal communications, people search networks / mens je and satellite mobile systems.

According to a preferred embodiment of the present invention, a low frequency control signal is multiplexed by the communications interface in the fiber network to provide a loopback alarm status of each unit remotely and to provide signals of control for it, which control the gain of the same amplifier.

According to a preferred embodiment of the present invention, plural antennas include at least one rotary mounting directional antenna whose direction can be adjusted in place.

Preferably, the unit also includes a tuning circuit system, which allows dynamic tuning and the transmit / receive balance of the cell size of each of the remote units.

The base unit can also include an interface for the management of the network, which allows the monitoring of the operating status of a base unit and the remote units connected to it.

Preferably, the fiber optic transmitter employs a vertical cavity surface emitting laser or an edge emitting laser coupled to a single mode or multimode fiber. The edge emitting laser can be a distributed feedback laser integrated with a unilateral optical isolator.

Additionally, according to a preferred embodiment of the present invention, a microcellular telecommunication system employing a fiber network including optical fibers, which can be single-mode or multimode and optical transmitters for transmitting signals along the optical fibers, the optical transmitters comprise a vertical cavity surface emitting laser.

BRVE DESCRIPTION OF THE DRAWINGS The present invention will be more fully understood and appreciated from the following detailed description, taken in conjunction with the drawings in which: Fig. 1 is a simplified pictorial illustration of part of a wireless communications station, constructed and operated in accordance with a preferred embodiment of the present invention; Fig. 2 is a simplified block diagram illustration of the circuit system employed in the apparatus of Fig. 1; Fig. 3 is a somewhat more detailed block diagram illustration of part of the circuitry of Fig. 2; Fig. 4 is a simplified block diagram illustration of a soft limiter, constructed and operable in accordance with a preferred embodiment of the present invention.

Fig. 5A is a simplified block diagram of part of the circuit system of Fig. 2, according to a preferred embodiment of the present invention; Fig. 5B is a simplified block diagram of part of the circuitry of Fig. 2, according to another preferred embodiment of the present invention, and includes a microprocessor control of remote units with antennas; Fig. 5C is a simplified illustration of a remote control unit for remotely controlling the control parameters of a local cell, according to a preferred embodiment of the present invention; Fig. 6 is a simplified block diagram illustration of the apparatus for operating the network in the apparatus of Figs. 1-5B; Y Fig. 7 is an illustration of the use of directional antennas in a system of the type illustrated in Figs. 1 - 6.

DETAILED DESCRIPTION OF A PREFERRED MODALITY Reference is now made to Figs. 1 and 2, which illustrate a multi-system station, which is part of a wireless communications system constructed and operating in accordance with a preferred embodiment of the present invention.

In a typical system, a plurality of wireless network services, such as PCS, GSM and other wireless telephone and radio services, as well as people search services, each communicate via an appropriate antenna (not shown) with one or more multi-system stations, such as those illustrated in Fig. 1. Each station can be a building, part of a building or a plurality of buildings, depending on the requirements of the system.

According to a preferred embodiment of the present invention, each station comprises a base unit 10, which communicates with each of the required wireless network services, typically via wide-bandwidth RF interface wired links, which they typically provide a GSM gateway, a GSM gateway, a PCS gateway, a PCS gateway and a people gateway gateway. It is appreciated that any of the different appropriate systems can also be connected to the base unit 10.

As seen in Fig. 2, the base unit 10 preferably comprises an input combiner 12, which combines the different appropriate inputs, such as the GSM, PCS and peer inputs in a combined output, typically in the shape of a multiplexed signal, and provides the multiplexed signal via the respective fiber-optic transmitters 14 and fiber-optic cables 16 to a plurality of remote units 20, which are typically distributed in different floors, or even in different rooms of one or more buildings or any of the interior or shaded areas, depending on the construction of the building and the requirements of the system.

Each remote unit 20 typically comprises a fiber-optic receiver 22, which receives the combined output, which is typically an RF output, and supplies it to a splitter 24, which is connected to individual antennas, such as antennas 30, 28 and 26 for the PCS, GSM and people search networks, respectively. The splitter divides the combined output, which is sent to the respective antennas 30, 28 and 26.

The antennas 26, 28 and 30 transmit the signals received via the combiner 12, transmitters 14, optical fibers 16, receivers 22, and dividers 24 to the subscriber units, such as cell phones 32 and people search devices 34 (Fig. . 1) .

In each remote unit 20, antennas 26, 28 and 30 preferably operate in a full (double) duplex mode and also receive signals from subscriber units, such as cell phones 32 that operate in one or more networks , such as, for example, GSM and PCS networks. These signals are supplied to a combiner 42, which combines the different wireless signal inputs, such as the GSM and PCS signals, into a combined output, typically in the form of a multiplexed signal, and provides the multiplexed signal via a transmitter. fiber-optic receiver 44 and a fiber-optic cable 46 to the base unit 10. The base unit 10 typically comprises a plurality of fiber-optic receivers 48, each corresponding to one of the remote units 20, which receive the combined signal through the fiber-optic cable 46. and it supplies an output splitter 20, which divides the combined signal into a plurality of individual signal outputs, such as, for example, a GSM output and a PCS output.

Reference is now made to Fig. 3, which illustrates the circuitry of the base unit 10 in a little more detail, showing the levels of the typical input signal and the frequency bands of the different input signals to the base unit. It is seen that the fiber optic transmitter typically comprises a laser diode 60. Preferably, the transmitter 14 employs a vertical cavity surface emitting laser or an edge emitting laser coupled to a single mode or multimode fiber 16.

Preferably, each fiber-optic receiver 48 comprises a photodiode 62, which converts the optical signal to RF. A 10 KHz detector 64 detects and filters a 10 KHz tone. If the 10 KHz tone is not detected, this is an indication of an interruption in the communication link and the detector 64 causes the illumination of a LED (Light Emitting Diode) pilot 66. Another indication of an interruption in the link of the communications is the absence of received light, which can be indicated by an optical alarm 68.

Reference is now made to Fig. 4, which illustrates a soft limiter 100, constructed and operable in accordance with a preferred embodiment of the present invention. In the uplink, one or more mobile telephones located very close to the remote antenna can overexcite the laser diode 60. The soft limiter 100 can be used in the uplink to prevent the laser diode 60 from being overexcited, and therefore prevent non-linear distortion in all distributed services. In the downlink, the soft limiter 100 protects any of the wireless services from inadvertently increasing the input power to the base unit 10.

The soft limiter 100 preferably includes a switched attenuator 102, a comparator 104 and an RF power level detector 106, as shown in Fig. 4.

Reference is now made to Fig. 5A, which is a block diagram of part of the circuit system of Fig. 2. There are a number of communication options per antenna with the communication system of the present invention. In the uplink portion of the communication system, the removable electrical bridges can be used to connect the GSM antenna 28 and the PCS antenna 30 to the local and / or remote antennas. Specifically, a removable electrical bridge 70 can be used to connect the GSM antenna 28 only to an internal antenna 72. An additional removable electrical bridge 72 can be used to connect the GSM antenna 28 to the local antenna 76, which is preferably the same internal antenna 72, and a remote antenna 78. The remote antenna 78 preferably is driven by DC to allow amplification and can be connected by a coaxial cable. The local antenna 76 and the remote antenna 78 are preferably connected via a power splitter / combiner 80. The aforementioned description applies equally to the PCS antenna 30, as shown in FIG. 5A.

The signals of each GSM antenna 28 and PCS antenna 30, each are input to a low noise amplifier (LNA) 82 via an antenna duplexer 84 to allow the same antenna to be used for transmission and reception. The signals from both the GSM antenna 28 and the PCS antenna 30 are combined by the combiner 42 and fed into the fiber-optic transmitter 44.

In the downlink, the optical signal of the base unit 10 is amplified and demultiplexed by the demultiplexer 85. Three signals are preferably demultiplexed. A 10 KHz tone is input to the transmitter 44, a low frequency people search signal is introduced to the loop antenna for the search of people 26, and an RF signal, comprising combined GSM and PCS signals, is introduces a demultiplexer 86. These signals are each input to their respective antenna via an antenna duplexer 84.

As seen in Fig. 5A, a gain control is provided on the receiver 22 and the transmitter 44. The gain level is controlled by the amplitude of the pilot tone of 10 KHz. The simultaneous gain control of the transmitted and received signals determines the size of the local cell.

Reference is now made to Fig. 5B, which illustrates the microprocessor control of the remote units 20. Instead of the analog control using the 10 KHz tone, a low frequency data signal can be multiplexed by the multiplexer 90 together with the RF signal. A microprocessor 92 in each remote unit 20 receives the signal. The absence of the signal indicates an alarm state, which the microprocessor 92 transmits to a microprocessor (not shown) in the base unit 10. The low frequency data signal can be used for the status and control of the remote unit. 20, and may include the following parameters: to. Cell size: This controls the gains of the signals transmitted and received b. Balance between the signals transmitted and received c. Limiter of the soft limiter 100.

The control parameters can be from the base unit 10 or can be controlled remotely through an interface for the management of the network. However, it is sometimes more convenient to set these control parameters locally, while the unit is tested in situ.

Reference is now made to Fig. 5C, which illustrates a remote control unit 110 for remotely controlling the control parameters of a local cell, according to a preferred embodiment of the present invention, the remote control unit 110 preferable includes a plurality of control buttons, such as the control button for the cell size 112 and a control button for the balance 114. For example, the control button 112 can control the volume, while the control button 114 can control the balance of the transmission cell, such as stereo balance. An additional control button 116 may be provided to control the threshold of the soft limiter 100.

Reference is now made to Fig. 6, which is a simplified block diagram illustration of the apparatus for operating the network useful in the apparatus of Figs. 1 - 5C. The network management apparatus typically comprises a microprocessor 200 which is typically communicated via an RS 232 interface 202 and a MODEM (modulator and demodulator) 204 with an external communications network, such as a telephone wire network. The microprocessor receives the status indications of the alarm indicators 206, which indicate the malfunctions in the remote units 20 (Fig. 1) based on the reception of the loop return signals thereof.

The microprocessor 200 provides gain control signals to the remote units via a D / A converter 208 and a loop return signal generator 210. The generator of the loop return signal 210 preferably operates at approximately 10 KHz .

Reference is now made to Fig. 7, which is an illustration of the use of directional antennas in a system of the type illustrated in Figs. 1-6. Fig. 7 shows the use of two such antennas, indicated by reference numerals 220 and 22, which are directed in different directions. Directionality is achieved by turning the plane to ground around the vertical antenna. The antennas 28 and 30 (Fig. 2) are preferably antennas of this type. This allows the tuning and balancing of cell size once the basic fixed installations have been made. This also allows tuning and future rolling to overcome obstacles or partitions, which can be built in the building in the future.

It will be appreciated by persons skilled in the art that the present invention is not limited in that it has been shown and described particularly in this document. Rather, the scope of the present invention is defined solely by the claims, which are shown below.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates.

Having described the invention as above, the content of the following is claimed as property.

Claims (1)

1. CLAIMS 1. A wireless communications station, characterized in that it comprises: a base unit comprising: a communication interface for communication with plural wireless communications networks; a communications combiner received to combine received communications signals received from plural communication networks into a single radio frequency output; a transmission communication splitter for dividing the previously combined transmission communications signals that are transmitted to plural wireless communications networks into plural radiofrequency outputs; at least one fribooptic transmitter that receives the unique radiofrequency output and provides a corresponding optical output; and at least one fiber optic receiver that receives an optical input and provides an RF output containing previously combined transmission communication signals; a plurality of units at a distance, each comprising: plural antennas for communicating with communicators along wireless communication networks; a communications splitter received for dividing the received communications signals previously combined from the base unit and supplying them to plural antennas; a transmission communications combiner for combining the transmission signals of the plural antennas into a combined radio frequency output; a fiber-optic transmitter that receives the combined radiofrequency output and provides a corresponding optical output, - and a fiber-optic receiver that receives the optical output and provides an RF output to the received communications splitter that contains the previously received transmission communications signals; a first optical fiber connecting each fiber-optic transmitter of the base unit with a corresponding fiber-optic receiver in a corresponding distance unit; Y a second optical fiber connecting each fiber-optic transmitter of a remote unit with a corresponding fiber-optic receiver in the base unit. The wireless communication station according to claim 1, characterized in that each remote unit comprises a diplexer interposed between each of the plural antennas and the combiner and the divider, to allow communications of two simultaneous routes via each antenna at different frequencies. for transmission and reception. 3. A mobile communication system, characterized in that it comprises a base unit comprising: a communication interface for communication with plural wireless communications networks; a plurality of antennas, each communicating are the communication interface via a fiber network; Y a single (double) duplex cable that interconnects each of the plurality of antennas with the communication interface via the fiber network. 4. The system according to claim 3, characterized in that the plural wireless communications networks comprise at least two communication networks selected from the group consisting of cellular telephone networks, cordless telephones, wide area data networks, urban area networks wireless, personal communication systems, personal communications networks, people / message networks and satellite mobile systems. 5. The wireless communication station according to claim 1 or 2, characterized in that the low frequency control signal is multiplexed by the communication interface in the optical fiber to provide a loopback alarm status of each remote unit and to provide control signals thereto, which control the gain and balance of the amplifier thereof. 7. The wireless communication station according to claim 1 or 2, characterized in that the plurality antennas comprise at least one rotary mounting directional antenna whose direction can be adjusted on the site. 8. The wireless communication station according to claim 1 or 2, characterized in that the base unit also comprises a tuning circuit system, which allows the dynamic tuning and the transmit / receive balance of the cell size of each. of the units at a distance. 9. The wireless communication station according to claim 1 or 2, characterized in that the base unit also comprises an interface for the management of the network, which allows the monitoring of the operating status of a base unit and the remote units connected to the base unit. the same. 10. The wireless communication station according to claim 1 or 2, characterized in that the fiber-optic transmitter employs a vertical cavity surface emitting laser coupled to a single mode or multimode fiber. 11. The wireless communication station according to claim 1 or 2, characterized in that the fiber-optic transmitter employs an edge-emitting laser coupled to a single mode or multimode fiber. 12. The wireless communication station according to claim 1 or 2, characterized in that it comprises a soft limiter to substantially prevent distortion due to an inadvertent increase in communication power. 13. The system according to claim 3 or 4, characterized in that the low frequency control signal is multiplexed by the communication interface in the optical fiber to provide a loopback alarm status of each unit remotely and to provide signals of control to it, which control the gain and balance of the same amplifier. 14. The system according to claim 3 or 4, characterized in that the low frequency data signal is multiplexed by the communications interface to a microprocessor to provide a loopback alarm status of each unit remotely and to provide signals of control for it, which control the gain and balance of the same amplifier. 15. The system according to claim 3 or 4, characterized in that the plurality antennas comprise at least one rotary mounting directional antenna whose direction can be adjusted on the site. 16. The system according to claim 3 or 4, characterized in that the base unit also comprises a tuning circuit system, which allows the dynamic tuning and the transmission / reception balance of the cell size of the units at a distance. 17. The system according to claim 3, characterized in that the base unit also comprises an interface for the management of the network, which allows the monitoring of the operating status of a base unit and the remote units connected to it. 18. The system according to claim 3 or 4, characterized in that the fiber-optic transmitter employs a vertical cavity surface emitting laser coupled to a single mode or multimode fiber. 19. The system according to claim 3 or 4, characterized in that the fiber-optic transmitter employs an edge-emitting laser coupled to a single mode or multimode fiber. 20. The system according to claim 3 or 4, characterized in that it comprises a soft limiter to substantially prevent distortion due to an inadvertent increase in the communication power. 21. A microcellular telecommunications system employing a fiber network, characterized in that it comprises optical fibers, which can be single-mode or multi-modes and optical transmitters for transmitting signals along the optical fibers, the optical transmitters comprise a surface emitting laser of vertical cavity. 22. A microcellular telecommunications system employing a fiber network, characterized in that it comprises optical fibers, which can be single-mode or multi-modes and optical transmitters for transmitting signals along the optical fibers, the optical transmitters comprise a laser emitter of edge. 23. A microcellular telecommunications system according to claim 22, characterized in that the edge emitting laser comprises a distributed feedback laser integrated with a unilateral optical isolator.