IE903116A1 - A radio-telephone communications network - Google Patents
A radio-telephone communications networkInfo
- Publication number
- IE903116A1 IE903116A1 IE311690A IE311690A IE903116A1 IE 903116 A1 IE903116 A1 IE 903116A1 IE 311690 A IE311690 A IE 311690A IE 311690 A IE311690 A IE 311690A IE 903116 A1 IE903116 A1 IE 903116A1
- Authority
- IE
- Ireland
- Prior art keywords
- radio
- mobile stations
- transmitter
- communications network
- transmission base
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04W—WIRELESS COMMUNICATION NETWORKS
- H04W84/00—Network topologies
- H04W84/02—Hierarchically pre-organised networks, e.g. paging networks, cellular networks, WLAN [Wireless Local Area Network] or WLL [Wireless Local Loop]
- H04W84/10—Small scale networks; Flat hierarchical networks
- H04W84/14—WLL [Wireless Local Loop]; RLL [Radio Local Loop]
Landscapes
- Engineering & Computer Science (AREA)
- Computer Networks & Wireless Communication (AREA)
- Signal Processing (AREA)
- Radio Relay Systems (AREA)
- Mobile Radio Communication Systems (AREA)
Abstract
The network according to the invention comprises at least one central telephone station (1), at least one fixed transmission base (2) linked to the central telephone station in order to secure a radio telephone interface and to communicate with mobile stations (6) by radio link, and at least one repeater station (7) associated with a transmission base (2) to secure a global radio link with the transmission base and the mobile stations.
Description
The present invention relates to radio-telephone communications network.
Radio-telephone communications networks are known which 5 comprise a series of telephone central stations connected to a series of fixed transmission bases distributed over a territory to be covered by the communications network and each including a plurality of assemblies each comprising a radio-telephone interface member, a transmitter, and a receiver for communicating with mobile stations over a radio link.
In existing networks, the fixed transmission stations are generally connected to the telephone central stations by cables.
A certain number of constraints apply to the installation of a transmission base, in particular a site must be available at sufficient altitude to enable antennas to be installed in the proximity of premises in which the members constituting the transmission base are installed. These constraints are particularly difficult to satisfy in towns where the presence of numerous buildings requires a transmission base to be installed on one of the highest buildings and where the acquisition or renting of premises are particularly expensive. Further, installing a transmission base at the top of a building requires telephone cables to be passed through the entire building and extended by an underground link. In order to solve this problem, proposals have been made to provide a radio link between the telephone central station and the transmission base. However this solution does not solve the problem of obtaining premises in the building where the antennas are to be installed.
Further, efforts are currently being made to reduce the volume and the cost of mobile stations more and more so as to make them usable by a larger number of users. Such a reduction in the volume and the cost of mobile stations implies reducing their power and thus their range. It is then necessary to multiply the number of cells occupying the territory to be covered by the communications network and consequently to multiply the number of transmission bases associated with the cells. The problems mentioned above with respect to installing a transmission base make it practically impossible with existing apparatuses to install a low power communications network in urban zones that have already been built.
An aim of the present invention is to provide a radiotelephone communications network minimizing problems of installing transmission bases.
In order to achieve this aim, the invention provides a radio-telephone communications network including at least one telephone central station, at least one fixed transmission base connected to the telephone central station for providing a radio-telephone interface and communicating with mobile stations over a radio link, and at least one repeater station associated with a transmission base for providing a global radio link between the transmission base and the mobile stations.
The term global radio link is used to mean a radio link transmitting the entire range of frequencies over which the various calls take place.
In an advantageous version, a repeater station includes a transmitter/receiver member for communication with the transmission base, said transmitter/receiver member being connected to a transmit line for transmitting radio signals to the mobile stations and to a receive line for receiving radio signals from the mobile stations, these two lines being connected both to a common oscillator for carrier frequency transposition between the frequency used for repeater station and base station communication and the frequency used for repeater station and mobile station communication, and to a respective transmit member or receive member for the link with the mobile stations.
The repeater stations are thus provided with a very small number of members that may be disposed in a compact housing associated with a mast carrying the antennas on the roof of a building. The installation of a repeater station thus no longer requires premises to be available, nor does it require cabling passing through the building, with the repeater station being powered by a battery or by a connection to the normal electricity mains serving the building, thereby enabling the Intended sites to be multiplied without difficulty.
Further, for a repeater station processing a multichannel radio link, there generally exists an extremely large dynamic range difference between the signals received from the mobiles, and this implies that the repeater station must have very high power to enable processing to be performed by a single member for transposition and amplification.
In another aspect, the present invention provides a radiotelephone communications network in which the repeater station includes a transmitter/reoeiver member for communicating with the transmission base, said member being connected to a transmit line for transmitting radio signals to the mobile stations and to a receive line for receiving radio signals from the mobile stations, the transmit line including a series of channels each comprising, in the signal propagation direction, a frequency band selector member, a carrier frequency transposition member, and an amplifier connected to a coupler member common to the channels, sAid coupler member being connected to a transmit member; the receive line including, in the signal propagation direction, a receive member, a preamplifier, a series of channels each comprising a band selector member, a gain control member associated with a variable gain amplifier, and a carrier frequency transposition member connected to a coupling member which is common to the channels and which is itself connected to the transmitter/reoei ver member; the carrier frequency transposition members of the transmit line and of the receive line being connected in pairs to common local oscillators.
Thus, the range of frequencies processed by each channel is reduced and the radio signals from the mobile stations are transferred by the gain control members to substantially the same dynamic level with reduced power consumption.
In a preferred aspect of the invention where the gain control members are too slow to ensure satisfactory transmis4
IE 9031 sion of signals having dynamic range jumps that are large and rapid, a preferred version of the invention provides a receive station including a transmitter/receiver member for communicating with the transmission base, said transmitter/reoeiver member being connected to a transmit line for transmitting radio signals to the mobile stations, and to a receive line for receiving radio signals from the mobile stations; the transmit line including, in the signal propagation direction, a receiver, a modulating bit extractor member associated with a series of channels each including a modulator member, a carrier frequency transposition member, and an amplifier connected to a coupling member which is common to the channels, said coupling member being connected to a transmit member; the receive line including, in the signal propagation direction, a receive member, a preamplifier, a series of channels each comprising a processing subassembly including a carrier frequency transposition and filter member, an amplifier member comprising fixed gain amplifier elements connected in parallel, an analogto-digital converter member, and a digital processor unit for generating weighted decision bits on the basis of digital signals from the analog-to-digital conversion member; the processing subassembly further Including, between the converter member and the digital processor unit, means for storing signals at different levels of gain, means for rereading the signals, for selecting a gain level which is adapted to the digital processor unit, and for transmitting the signals stored at said gain level to the digital processor unit; the channels being connected to a multiplexer member associated with a transmitter connected to the transmitter/reoeiver member; the carrier frequency transposition members of the transmit line and of the receive line being connected in pairs to respective common local oscillators, and the modulating bit extractor member being connected to the transmitter and to the processing subassembly of each receive line channel in order to transfer control and synchronization information.
Further, in present transmission bases, even when they are installed in regions having very low communications density (in
IE 90311b particular ln rural zones), It Is necessary to provide each transmission base with at least two transmitter/receiver and radio-telephone Interface assemblies, one of these assemblies being used for normal operation and the other being provided for use in the event of the first assembly misfunctioning, with the assembly that is in service not being used at maximum capacity. This disposition is particularly expensive. In another aspect of the invention, a plurality of receiver stations are associated with the same transmission base, with the number of transmitter/receiver and radio-telephone interface member assemblies being determined as a function of the number of calls that are to be conveyed by the transmission base and by all of the receiver stations associated therewith. This ensures that a territory can be covered using a much smaller number of transmitter/receiver and radio-telephone interface member assemblies than is possible using existing separate transmission bases.
Preferably, when availability of communications frequencies make it possible, the receiver stations used the same range of carrier frequencies to communicate both with the transmission base and with the mobile stations. This further reduces the cost of an installation.
Embodiments of the invention are described by way of example with reference to the accompanying figures, in which:
Figure 1 is a diagram of a radio-telephone communications network of the invention;
Figure 2 is a diagram of the structure of a repeater station of the invention;
Figure 3 is a diagram of a variant radio-telephone communications network of the invention;
Figure 4 is a diagram of a second embodiment of a repeater station of the invention;
Figure 5 is a diagram of a third embodiment of a repeater station of the invention;
Figure 6 is a detail diagram of a portion of the Figure 5 apparatus; and
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Figure 7 is a detail diagram of a portion of the Figure 6 apparatus.
With reference to Figures 1 and 2, the radio-telephone communications network of the invention comprises a telephone central station 1 connected to fixed transmission bases 2 by telephone cables 3. In the embodiment shown, transmission base
2.1 is conventional in structure being fitted with a transmit antenna 4.1 and a receive antenna 5.1 for communicating directly with mobile stations 6. In contrast, according to the invention, transmission bases 2.2 and 2.3 are associated with respective repeater stations 7.2 and 7.3.
The repeater stations 7 are linked by radio with the respective transmission bases with which they are associated, e.g. by means of respective transmit/receive antennas 8 carried by the repeater stations and transmit/receive antennas 9 carried by the transmission bases. Since the repeater stations and the transmission bases are fixed, it is preferable to use antennas which are highly directional. The transmit/receive antenna 8 of a repeater station (see Figure 2) is connected via a duplexing member 10 to a transmit line 11 for transmitting radio signals to the mobile stations, and to a receive line 12 for receiving radio signals from the mobile stations, both lines being connected to a common oscillator 13 for providing carrier frequency transposition between the frequencies used by the repeater station for communication with the base station and for communication with the mobile stations. The transmit line 11 is further provided with a transmit antenna 4 (specifically 4.2 for repeater station 7.2 and 4.3 for repeater station 7.3) and the receive line 12 is connected to a receive antenna 5 (specifically 5.2 for repeater station 7.2 and 5.3 for repeater station 7.3) for providing communication with the mobile stations.
It may be observed that the repeater station provides no processing of the transmitted communications signals and repeats the radio signal globally, with the only processing being transposition of the carrier frequency range which may be about 38 GHz for communication with the transmission base, for example, to a frequency range of about 2 GHz for communication with the mobile stations, preferably together with ampl if ication of the repeated radio signals, with the transposition to 38 GHz for communication between the repeater station and the trans5 mission base serving merely to economize available frequencies close to 2 GHz for communication with the mobile stations.
It may be observed that in addition to the ease of installing a repeater station as already emphasized above, a radio-telephone communications network of the invention has the further advantage of enabling the transmission bases to be brought together in a single premises, which may indeed be the same premises as that housing the telephone central station, thereby enabling the transmission bases to make use of certain members in common. Further, maintenance or repair activity on the transmission bases is facilitated by having them together. Figure 3 shows a variant embodiment for covering a territory over which the small number of calls does not justify vising a transmission base for each cell, i.e. for each elementary zone of the territory, and where the number of frequencies available in a given frequency range, e.g. about 2 GHz, is large relative to the number of frequencies required for providing communication with the mobile stations (not shown).
In this case, the transmission base 2.1 is associated with a plurality of repeater stations 7.11, 7.12, and 7.13. The transmission base includes an omnidirectional transmit antenna
4.1 and an omnidirectional receive antenna 5.1 enabling it to communicate directly either with a mobile station when the mobile station is close to the transmission base, or else with one of the repeater stations, which stations are fitted for this purpose with directional receive antennas 14 (respectively numbered 14.11, 14.12, and 14.13), and directional transmit antennas 15 (respectively numbered 15.11, 15.12, and 15.13), looking at the base station.
When signals transmitted by the transmission base, they are received by mobile stations in the direct transmission range of the transmission base, and by all of the repeater stations which repeat using carrier frequency offsets that are
IE 90311b specific to each repeater station so as to avoid setting up interference for a mobile station lying in the transmission field of two adjacent repeater stations.
Similarly, all of the signals received by the repeater 5 stations at a given instant are retransmitted with a shift in carrier frequency to the transmission base, which, in fact, receives only those signals that are at a frequency to which the transmission base is set at said instant.
It may be observed that in this embodiment, not only is there a saving in the number of transmitter/receiver and radiotelephone interface member assemblies that would otherwise need installing ln conventional transmission bases spread over the territory, but also there is a saving in high frequency communications members (e.g. at 38 GHz) compared with the apparatus of Figures 1 and 2. However, this embodiment uses up more of the frequencies in the frequency range under consideration.
For example, in a, territory comprising seven cells, having a central cell surrounded by six peripheral cells, with each cell being capable of serving traffic equal to two Erlangs, a conventional network would use seven transmission bases each comprising a normal eight-channel transmitter/receiver and radio-telephone interface member assembly and a spare assembly, giving a total requirement of 14 assemblies. Since the total number of Erlangs served over the entire territory is 14, it could be served by a transmission base having only five transmitter/receiver and radio-telephone interface member assemblies (four normal assemblies and one spare assembly), with said base being associated with six repeater stations.
When the number of calls to be conveyed justifies associating a transmission base with a plurality of repeater stations without there being an adequate number of available frequencies in a single frequency range for providing the links between the transmission base and the repeater stations, said links may be provided at a different frequency, e.g. 38 GHz, in which case the transmission base and the repeater stations need to be fitted with members appropriate for providing such transmi ss ion.
With reference to Figure 4, a first embodiment of a repeater station 7 comprises a transmitter/receiver member 8 for communicating with the transmission base, said member being connected via a duplexing member 10 to a transmit line given an overall reference 11 for transmitting radio signals to the mobile stations, and to a receive line given an overall reference 12 for receiving radio signals from the mobile stations. The transmit line 11 includes a series of channels 21 of which only two are shown in Figure 4, each channel comprising, in the signal propagation direction: a frequency band selector member 22, a carrier frequency transposition member 23, and an amplifier 24 connected to a coupling member 25 which is common to the various channels, said coupling member 25 being connected to a transmit member 4.
in the signal propagation direction, the receive line 12 comprises a receive member 5 and a free amplifier 6 connected to a series of channels 27 of which only two are shown in Figure 4. Each channel 27 comprises a band selector member 28 connected to a gain control member 29 associated with a variable gain amplifier 30. The variable gain amplifier 30 is itself connected to a carrier frequency transposition member 31 connected to a common coupling member 32 for the various channels 27, said coupling member being itself connected to the transmitter/receiver member 8 via the duplexing member 10. The carrier frequency transposition member 23 in the transmit line 11 and 31 in the receive line 12 are connected in pairs to common local oscillators 13.
With reference to Figures 5 to 7, a preferred embodiment of a repeater station 7 of the invention comprises, as in the case shown in Figure 4, a transmitter/receiver member 8 associated with a transmit line 11 and with a receive line 12 via a duplexer 10. In this case, the transmit line 11 comprises, in the signal propagation direction, a receiver 33 connected to a member 34 for extracting modulating bits associated with a series of channels 35, only one of which is shown in Figure 5. Each channel 35 comprises a modulator member 36, a carrier frequency transposition member 37, and an amplifier 38 connected to a coupling member 39 which is common to the various channels and is itself connected to a transmit member 4.
In the signal propagation direction, the receive line 12 5 comprises a receiver member 5 connected to a preamplifier 40 associated with a series of channels 41, only one of which is shown in Figure 5. Each channel 41 comprises a processing subassembly 42 connected to a multiplexer member 43 which is common to the various channels and which is itself connected to a transmitter 44 connected to the transmitter/receiver member 8 via the duplexer member 10. The modulating bit extractor member 34 is also connected by a line 45 to the processor subassembly 42 and to the transmitter 44 in order to transmit the control and synchronizing information thereto necessary for their operation.
The processing subassembly 42 is shown in greater detail in Figures 6 and 7. This processing subassembly comprises a filtering and carrier frequency transposition member 102 including a first band filter 104 (Figure 7) for selecting the corresponding frequency band of the channel 41. The output from the band filter 104 is connected to an input of a carrier frequency transposition member constituted by a mixer 105 having another input connected to a local oscillator 106 whose second output is connected by a line 46 to the carrier frequency transposition member 37 of the transmit line 11. The output from the mixer 105 is connected to a filter 107 centered on the frequency of the local oscillator 106 and having a wide passband equal in width to the passband of the signal to be processed.
The output from the filtering and carrier frequency transposition member 102 is connected to an amplifier member 108 comprising a first amplifier stage having two fixed gain amplifiers 109 connected in parallel (see Figure 7).
In the embodiment shown, one of the amplifiers 109 has a gain of g adapted to the most powerful signal that the processing subassembly is expected to receive, whereas the other amplifier 109 has a gain of g plus 40 dB. The amplifiers
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109 are followed by mixers 110 each having a first input connected to a respective one of the amplifiers 109 and a second input connected to a local oscillator 111 whose function is to perform frequency transposition in order to center the signal on a frequency Fb/2 where Fb is the bit frequency of the signal. Each of the mixers 110 is followed by a filter 112 for eliminating residues. The output from each filter 112 is connected in parallel to four output lines 113. In each group of output lines 113, one of the lines has no amplifier, a second line includes an amplifier 114 having a gain of 10 dB, a third line includes an amplifier 115 having a gain of 20 dB, and a fourth line includes an amplifier 116 having a gain of 30 dB, which amplifiers constitute a second amplification stage of the amplifier member 108. As a result, the output lines 113 provide levels of amplification spread over 0 dB to 70 dB of amplification relative to the input signal to amplifier member 108.
The output lines 113 of the amplifier member 108 are connected to respective inputs of a sampler 117 including a series of connection means 118 connected in parallel and controlled by a control member 119 in order to establish connections cyclically between a common analog-to-digital converter member 120 and one of the lines 113 at a time. In the embodiment described, where the converter member Is common to all levels of amplification, the sampling frequency is 2.Fb for each line 113, i.e. 16.Fb for the sampler so as to obtain meaningful sampling of the received signals.
The output from the converter member 120 is connected to an input of storage means 121 having another input connected to the control member 119 so that each sample received from the converter member 120 is given an address which corresponds to the line 113 associated with the stored sample. The storage means 121 are connected to stored signal selection means 122 which read all of the samples of a packet as stored at each level of amplification, and which select the most suitable level of amplification as a function of criteria given to the selection means, e.g. mean energy level or number of occasions on which clipping occurs.
In addition, the storage means 121 and the stored signal selection means 122 are connected to a digital processor unit 123 such that after determining the most appropriate level of amplification for the packet which has just been received, the stored signal selection means transmit information on this level of amplification to the digital processor unit and simultaneously cause the set of samples obtained at this level of amplification to be transferred from the storage means 121 to the digital processor means 123.
It may be observed that for each packet, the amplification level is selected after all of the bits in a packet have been stored. Selection is thus performed not only on the nonmeaningful bits of a packet, but also on the meaningful bits, thereby ensuring that very high quality selection is obtained.
Further, since selection is performed on each received packet, it is particularly well adapted even when the received signal level varies greatly from one packet to another.
The digital processor unit 123 equalizes the bits received using conventional methods and delivers decoded weighted decision bits which are transmitted to the multiplexer member 43. In this context it may be observed that the equalization operation is a partial processing operation which requires an installation which is neither very complex nor very powerful, and which may therefore easily be processed by a repeater station.
Naturally, the invention is not limited to the embodiment described and variants may be devised without going beyond the scope of the invention. In particular, although the repeater stations of Figure 2 are described as having a transmitter/ receiver member including a single transmit/receive antenna associated with a duplexer for establishing the link between each receiver station and the associated transmission base, the single antenna could be replaced by a transmit antenna and a receive antenna respectively associated with the transmit line and the receive line of the repeater station, as illustrated in
Figure 3, with the transmission base then itself being fitted both with a transmit antenna and with a receive antenna.
Claims (9)
1/ A radio-telephone communications network including at least one telephone central station, at least one fixed transmission base connected to the telephone central station for providing a 5 radio-telephone interface and communicating with mobile stations over a radio link, wherein the network Includes at least one repeater station associated with a transmission base for providing a global radio link between the transmission base and the mobile stations.
2. / A radio-telephone communications network according to claim 1, wherein the repeater station includes a transmitter/receiver member for communication with the transmission base, said transmitter/receiver member being connected to a transmit line 15 for transmitting radio signals to the mobile stations and to a receive line for receiving radio signals from the mobile stations, these two lines being connected both to a common oscillator for carrier, frequency transposition between the frequency used for repeater station and base station 20 communication and the frequency used for repeater station and mobile station communication, and to a respective transmit member or receive member for the link with the mobile stations.
3. / A radio-telephone communications network according to claim 25 1 or claim 2, including a plurality of repeater stations associated with a common transmission base.
4. / A radio-telephone communications network according to any one of claims 1 to 3, wherein communications between repeater 30 stations and the transmission base, and between the repeater stations and the mobile stations all take place in the same range of carrier frequencies.
5. / A radio-telephone communications network according to claim 35 l, wherein the repeater station includes a transmitter/receiver member for communicating with the transmission base, said member being connected to a transmit line for transmitting radio signals to the mobile stations and to a receive line for receiving radio signals from the mobile stations, the transmit line including a series of channels each comprising, in the signal propagation direction, a frequency band selector member, 5 a carrier frequency transposition member, and an amplifier connected to a coupler member common to the channels, said coupler member being connected to a transmit member; the receive line including, in the signal propagation direction, a receive member, a preamplifier, a series of channels each 10 comprising a band selector member, a gain control member associated with a variable gain amplifier, and a carrier frequency transposition member connected to a coupling member which is common to the channels and which is Itself connected to the transmitter/receiver member; the carrier frequency 15 transposition members of the transmit line and of the receive line being connected in pairs to common local oscillators.
6. / A radio-telephone communications network according to claim 1, wherein the receive station includes a transmitter/receiver 20 member for communicating with the transmission base, said transmitter/reoeiver member being connected to a transmit line for transmitting radio signals to the mobile stations, and to a receive line for receiving radio signals from the mobile stations; the transmit line including, in the signal 25 propagation direction, a receiver, a modulating bit extractor member associated with a series of channels each including a modulator member, a carrier frequency transposition member, and an amplifier connected to a coupling member which is common to the channels, said coupling member being connected to a 30 transmit member; the receive line including, in the signal propagation direction, a receive member, a preamplifier, a series of channels each comprising a processing subassembly including a carrier frequency transposition and filter member, an amplifier member comprising fixed gain amplifier elements 35 connected in parallel, an analog-to-digital converter member, and a digital processor unit for generating weighted decision bits on the basis of digital signals from the analog-to-digital IE 90311^ conversion member; the processing subassembly further including, between the converter member and the digital processor unit, means for storing signals at different levels of gain, means for rereading the signals, for selecting a gain 5 level which is adapted to the digital processor unit, and for transmitting the signals stored at said gain level to the digital processor unit; the channels being connected to a multiplexer member associated with a transmitter connected to the transmitter/receiver member; the carrier frequency 10 transposition members of the transmit line and of the receive line being connected in pairs to respective common local oscillators, and the modulating bit extractor member being connected to the transmitter and to the processing subassembly of each receive line channel in order to transfer control and 15 synchronization information.
7. / A radio-telephone communications network according to claim 6, wherein the processor subassembly includes a converter member common to a plurality of amplifiers, said common 20 converter member being connected to the associated amplifiers by a controlled switching member which is controlled to establish a connection cyclically between the common converter member and different ones of the amplifiers. 25
8. / A radio-telephone communications network according to claim 6 or claim 7, wherein the amplifier member includes a plurality of amplification stages connected in series in each of which the amplifiers are connected in parallel in a generally pyramid-shaped structure.
9. / A radio-telephone communications network substantially as herein described with reference to Figures 1 to 3 of the accompanying drawings. 35 10/ A radio-telephone communications network substantially as herein described with reference to Figures 4 to 7 of the accompanying drawings.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR8911340A FR2651394B1 (en) | 1989-08-29 | 1989-08-29 | RADIO-TELEPHONE COMMUNICATION NETWORK. |
| FR9000488A FR2657204A2 (en) | 1989-08-29 | 1990-01-17 | RADIO-TELEPHONE COMMUNICATION NETWORK. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| IE903116A1 true IE903116A1 (en) | 1991-03-13 |
Family
ID=26227532
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| IE311690A IE903116A1 (en) | 1989-08-29 | 1990-08-28 | A radio-telephone communications network |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0415810A1 (en) |
| FI (1) | FI904122A0 (en) |
| FR (1) | FR2657204A2 (en) |
| IE (1) | IE903116A1 (en) |
| NO (1) | NO903776L (en) |
| PT (1) | PT95116A (en) |
Families Citing this family (15)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2272599A (en) * | 1992-11-12 | 1994-05-18 | Nokia Telecommunications Oy | A method of cellular radio communication and a cellular radio system for use in such method |
| SE500620C2 (en) * | 1992-12-11 | 1994-07-25 | Televerket | Repeat function for short range radio systems |
| SE516173C2 (en) * | 1993-02-16 | 2001-11-26 | Ericsson Telefon Ab L M | Device for telecommunications |
| FR2703199B1 (en) * | 1993-03-26 | 1995-06-02 | Matra Communication | Radio transmission method using repeating spectrum inverting stations. |
| DE4326523A1 (en) | 1993-08-06 | 1995-02-09 | Siemens Ag | Universal mobile telecommunication system |
| ES2102956B1 (en) * | 1994-07-27 | 1998-04-01 | Alcatel Standard Electrica | DUAL FIXED-MOBILE COMMUNICATIONS SYSTEM. |
| US5890055A (en) * | 1995-07-28 | 1999-03-30 | Lucent Technologies Inc. | Method and system for connecting cells and microcells in a wireless communications network |
| DE29601436U1 (en) * | 1996-01-29 | 1996-04-18 | Impex Gesellschaft für elektronische Alarmanlagen mbH, 47441 Moers | Radio-controlled signaling and receiving system |
| DE19737897C2 (en) * | 1997-08-29 | 1999-07-22 | Dirc Gmbh & Co Kg | Data transmission system |
| US7248559B2 (en) | 2001-10-17 | 2007-07-24 | Nortel Networks Limited | Scattered pilot pattern and channel estimation method for MIMO-OFDM systems |
| US8811339B2 (en) | 2008-07-07 | 2014-08-19 | Blackberry Limited | Handover schemes for wireless systems |
| US8547861B2 (en) | 2008-07-07 | 2013-10-01 | Apple Inc. | Optimizing downlink communications between a base station and a remote terminal by power sharing |
| US8315229B2 (en) | 2008-07-07 | 2012-11-20 | Research In Motion Limited | Methods and apparatus for wireless communication |
| US8340235B2 (en) | 2008-09-25 | 2012-12-25 | Research In Motion Limited | X-MIMO systems with multi-transmitters and multi-receivers |
| JP5699151B2 (en) * | 2009-09-24 | 2015-04-08 | アップル インコーポレイテッド | Method for facilitating radio communication, radio signal repeater apparatus, radio communication method, and mobile station apparatus |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3487310A (en) * | 1965-02-03 | 1969-12-30 | Page Communications Eng Inc | Communication transponder technique |
| DE2256081C2 (en) * | 1972-11-16 | 1974-10-17 | Licentia Patent-Verwaltungs-Gmbh, 6000 Frankfurt | Telecommunication system with communication between fixed and mobile subscriber stations via relay stations |
| JPS5854742A (en) * | 1981-09-29 | 1983-03-31 | Nec Corp | Frequency converting type repeater |
| US4528656A (en) * | 1982-07-02 | 1985-07-09 | Harris Corporation | Radio communication system using frequency division multiplexing for transmission between a master station and a plurality of remote stations |
| US4849963A (en) * | 1985-10-15 | 1989-07-18 | Minori Kawano | Cellular radio telephone enhancement circuit |
| US4783843A (en) * | 1986-05-23 | 1988-11-08 | Peninsula Engineering Group, Inc. | Split band filter for cellular mobile radio |
| GB8629159D0 (en) * | 1986-12-05 | 1987-01-14 | British Telecomm | Mobile radio systems |
-
1990
- 1990-01-17 FR FR9000488A patent/FR2657204A2/en active Pending
- 1990-07-27 EP EP90402173A patent/EP0415810A1/en not_active Withdrawn
- 1990-08-20 FI FI904122A patent/FI904122A0/en not_active IP Right Cessation
- 1990-08-28 NO NO90903776A patent/NO903776L/en unknown
- 1990-08-28 IE IE311690A patent/IE903116A1/en unknown
- 1990-08-28 PT PT9511690A patent/PT95116A/en unknown
Also Published As
| Publication number | Publication date |
|---|---|
| PT95116A (en) | 1992-04-30 |
| FR2657204A2 (en) | 1991-07-19 |
| NO903776L (en) | 1991-03-01 |
| NO903776D0 (en) | 1990-08-28 |
| EP0415810A1 (en) | 1991-03-06 |
| FI904122A0 (en) | 1990-08-20 |
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