Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L5/00—Arrangements affording multiple use of the transmission path
  • H04L5/02—Channels characterised by the type of signal
  • H04L5/023—Multiplexing of multicarrier modulation signals, e.g. multi-user orthogonal frequency division multiple access [OFDMA]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/20—Control channels or signalling for resource management
  • H04W72/23—Control channels or signalling for resource management in the downlink direction of a wireless link, i.e. towards a terminal
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W76/00—Connection management
  • H04W76/10—Connection setup
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L27/00—Modulated-carrier systems
  • H04L27/26—Systems using multi-frequency codes
  • H04L27/2601—Multicarrier modulation systems
  • H04L27/2697—Multicarrier modulation systems in combination with other modulation techniques
  • H04L27/2698—Multicarrier modulation systems in combination with other modulation techniques double density OFDM/OQAM system, e.g. OFDM/OQAM-IOTA system
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W72/00—Local resource management
  • H04W72/04—Wireless resource allocation
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W76/00—Connection management
  • H04W76/20—Manipulation of established connections
• • 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]
  • H04W84/04—Large scale networks; Deep hierarchical networks
  • H04W84/042—Public Land Mobile systems, e.g. cellular systems

Definitions

• Cellular radio signal with additional channel assigned in the downlink corresponding process, system, mobile and base station.
• the field of the invention is that of cellular radiotelephony. More specifically, the invention relates to the transmission of data, in particular at high bit rates, in a radiotelephony system.
• Known radiotelephone systems such as G.S.M, are mainly dedicated to voice communications. They implement two symmetrical channels: a downlink (from a land base station to a mobile station) and an uplink (from the mobile station to the base station).
• the UMTS standard defined by ETSI provides for a symmetrical distribution between the downlink and the uplink.
• the invention applies in particular to these systems. It can also be applied to satellite systems (GLOBALSTAR, ICO, IRIDIUM, ).
• the invention particularly aims to provide a solution adapted to these new needs.
• an objective of the invention is to provide a new technique of cellular radiotelephony, allowing the transmission of data at high speed, to radiotelephony mobiles.
• Another objective of the invention is to provide such a technique, which is compatible with known standards, and in particular the UMTS standard such as defined by ETSI.
• the invention also aims to provide such a technique, which optimizes the use of the available resource, and which is based on a transmission method particularly suitable for the transmission of high speed data.
• an objective of the invention is to offer an available bit rate of at least
• Another objective of the invention is to provide such a technique, which allows the making of mobiles that are relatively simple technically, and therefore inexpensive, and suitable for the reception of different types of data (voice communications and high speed data in particular).
• the invention also aims to provide such a technique, allowing reception of high speed data, even under unfavorable reception conditions (high travel speed, of the order of at least 250 km / h, and journeys multiple in particular). Yet another objective of the invention is to provide such a technique, which allows an optimized and flexible allocation of the transmission resource, between one or more mobiles, at a given time. In particular, an objective of the invention is to allow the sharing of the high speed transmission resource between several operators.
• a cellular radiotelephone signal of the type comprising a symmetrical bidirectional main channel, comprising a main uplink and a downlink. main, ensuring in particular the transmission at low or medium speed of data and signaling and control information, and also comprising at least one additional channel assigned in the downward direction only, ensuring in particular the transmission of data at high speed.
• the invention therefore proposes a completely new signal structure, within the framework of radiotelephony systems, and more generally of telephony. Indeed, all these systems rest on a symmetrical structure (resting on the structure of voice communications). On the other hand, the technique of the invention is based on an entirely new asymmetrical approach, which is particularly suitable for new broadband applications.
• the invention proposes the addition, to a conventional symmetrical channel, of an additional channel that is only downlink, and dedicated to the transmission of high speed data, such as files transmitted over the Internet network.
• all or part of the transmission capacity of said additional channel is allocated dynamically to a particular mobile.
• the resource is allocated dynamically, only when necessary. It can be distributed, frequently and / or temporally, between several, mobile. When the demand is not significant, only a part of the resource (frequency or time) is allocated.
• said main downlink channel and said additional channel have synchronous frame structures.
• said additional channel also ensures the transmission of signaling and control information.
• said additional channel can ensure at least the transmission of signaling and control information intended for the mobile (s) during the transmission of data intended for said mobile, on said additional channel.
• said additional channel carries broadband data intended for said mobile
• said signaling and control information intended for a mobile is duplicated or switched from said main downlink to said additional channel.
• the mobile can receive, at a given time, only one or the other of the channels. This makes it possible to greatly simplify the structure of the receiver, by sharing at least part of the reception means.
• said main channel implements a spread spectrum access technique (CDMA).
• CDMA spread spectrum access technique
• the invention applies to the UMTS system.
• said additional channel implements a multicarrier technique ensuring a distribution of the data in time / frequency space.
• multicarrier technique is meant the implementation of a carrier frequency multiplex (for example according to the OFDM technique).
• . m is an integer representing the frequency dimension
• . n is an integer representing the time dimension
• . t represents time
• . T is the symbol time
• n is a real numerical coefficient chosen from a predetermined alphabet
• . 3 is the IOTA prototype function (as defined in FR-95 05455).
• the transmission capacity of said additional channel is allocated to a given mobile, dynamically, in the form of at least one "block” defined in time / frequency space.
• block here is meant a subset of the time-frequency space, defined by a given time interval and a frequency band. Geometric structures more complex than a "block” are of course conceivable (and possibly decomposable into “sub-blocks”).
• said signaling and control information for said main downlink comprises information for locating said blocks in time / frequency space.
• At least some of said blocks carry time and / or frequency synchronization references.
• the invention also relates to systems and methods for cellular radiotelephony using such a signal.
• the invention also relates to the mobiles of such a cellular radio telephone system.
• This mobile comprises in particular means for receiving at least one additional channel assigned in the downward direction only, ensuring in particular the transmission of high speed data.
• such a mobile comprises unique synchronization means implementing an analysis of said channel main and delivering synchronization information to means for processing said main channel and to means for processing said additional channel.
• the mobile comprises a single reception chain comprising in particular means for transposing a received signal to an intermediate frequency and means for demodulating the transposed signal, said received signal being able to be selectively said main downlink or said additional channel.
• the mobile also includes means for recovering said signaling information and for selectively controlling on said main downlink or on said additional channel.
• the invention also relates to the base stations of such a cellular radio telephone system, comprising in particular means for transmitting at least one additional channel assigned in the downlink direction only, ensuring in particular the transmission of high speed data.
• such a base station comprises means for transmitting signaling and control information intended for a given mobile on said additional channel, when the latter carries broadband data intended for said mobile.
• FIG. 1 recalls the allocation of frequency bands according to the UMTS standard and illustrates how it can be adapted for the signal of the invention
• FIG. 2 illustrates an example of allocation of the high-speed resourcing of the signal of FIG. 1
• FIG. 3 presents a block diagram of a first embodiment of a mobile receiver according to the invention
• FIG. 4 presents a block diagram of a second embodiment of a mobile receiver according to the invention.
• the invention is based on the UMTS standard defined by ETSI. It therefore uses the following frequency bands, illustrated in Figure 1:
• a downlink 12 and an uplink 12 2 of 30 MHz each for satellite exchanges (ICO); two channels 13 d and 13 2 TD-CDMA, the role of which was not yet defined, and the invention of which proposes a particular implementation.
• a combination of channels is used.
• a symmetrical low-speed channel in WCDMA (1 l d and 11 2 ) and a downlink high-speed transmission channel using a multicarrier system 13 2 are combined.
• Track 13 ! is for example assigned to domestic applications.
• the downward path according to the invention is preferably selected the path
• Channel 13 2 can use conventional multicarrier modulation, such as that implemented in OFDM systems (see for example the DAB ("Digital Audio Broadcasting") standard for radio broadcasting).
• DAB Digital Audio Broadcasting
• IOTA modulation which proves to be particularly suitable for the invention.
• the principle and the implementation of IOTA modulation are described in patent application FR-95 05455, incorporated by reference.
• This channel is a low speed channel (for example 8 or 16 kbit / s) this channel is used in a conventional manner on the uplink 11 2 , so as to transmit the signaling and the data originating from the user.
• the network allocates to this user an additional resource on the IOTA 13 2 channel.
• the downlink WCDMA channel 11 j transmits control information making it possible to describe the complementary resource dynamically allocated to the user concerned.
• This resource is described for example as the coordinates of a "block” of the time / frequency plan, in which the data will be transmitted.
• a mode of definition of these "blocks" in the time / frequency plane is presented below in relation to FIG. 2.
• the downlink WCDMA channel 11 j is always active.
• the channel at the IOTA 13 rate 2 is used exclusively for transmitting data.
• the signaling is always transmitted via the downward WCDMA channel ll j .
• a drawback of this first embodiment is that it supposes the simultaneous reception of the downlink WCDMA channel 11 d and of the IOTA channel 13 2 .
• a second embodiment which overcomes this drawback consists in switching all of the information from the downlink (signaling is given) on the high speed channel IOTA 13 2 for the duration of the transmission of the allocated "block". In this case, part of the allocated resource is reserved for signaling.
• This mode is more complex to manage, from the point of view of signaling, 10
• the system includes two types of physical channels: channels
• WCDMA and IOTA channels share a common frame structure.
• the set of signals can be described from a common clock at 4.096MHz.
• the transmission unit is the "slot", with a duration of 625 ⁇ s.
• the elementary frame has a duration of 10 ms, or 16 slots.
• a 720 ms multiframe is also defined.
• WCDMA channels use a 4.096 MHz "chip rate”, or 2560 chips (signal unit) per "slot” or 40960 “chips” per frame.
• chip rate or 2560 chips (signal unit) per "slot” or 40960 “chips” per frame.
• ARIB Association of Radio Industries and Business
• the signal transmitted includes in particular all the references necessary for time and frequency synchronization of the mobile.
• the IOTA channel uses a symbol time T of 125 ⁇ s or 62.5 ⁇ s, or 5 or 10 symbols per slot respectively or 512 or 256 chips per symbol.
• the spacing between carriers is 4 KHz in the first case and 8 KHz in the second case.
• . m is an integer representing the frequency dimension
• . n is an integer representing the time dimension
• . t represents time
• T is the symbol time
• a mn is a real numerical coefficient chosen from a predetermined alphabet
• . 3 is the IOTA prototype function (as defined in FR-95 05455).
• a "block" is defined for example by framing relationships of the time index n and the frequency index m, as illustrated in FIG. 2.
• a block is allocated to a particular user .
• the location of this block is very simply identified by its two “ends” 25 t (m l5 n j ) and 25 2 (m 2 , n 2 ).
• the resource is easily shareable over time (no presupposition of what there is before or after block 21), and in frequency.
• the frequency band can be shared, for example with block 22. When there is no need, no transmission is carried out.
• part of the frequency band 23 may not be modulated.
• Part of the data in the "block" can be reserved for the transmission of information transmitted the rest of the time on the main channel, as discussed below.
• the antenna 32 is connected to each of the reception channels via a duplexer 33 having two outputs 34 j and 34 2 corresponding respectively to the bands 2110-2170 MHz or 2010-2025 MHz, each output being connected to a reception chain.
• This duplexer 33 also includes an input 35 12
• This input is connected to a power amplifier 36.
• Each reception chain 31 j , 31 2 comprises: a low noise amplifier (LNA) 37 j and 37 2 ; - a mixer 38, 38 2 and a synthesizer 39 j , 39 2 making it possible to transpose one of the two preceding bands into intermediate frequency; an IF filter 310 j , 310 2 with a bandwidth of the order of 5 MHz; an IQ converter 311 j , 311 2 to baseband, controlled by a synthesizer 312 j , 312 2 ; an analog / digital converter (ADC) 313 JJ, 313 j Q and 313 2 ⁇ , 313 2I Q on each of the channels I and Q, with a sampling frequency of 8.192 MHz.
• the digital processing (demodulation, decoding) is carried out by a signal processing processor (DSP) 314 associated with two accelerators
• “hardware” a correlator for the realization of the "rake filter” necessary for the demodulation of the CDMA signal (314 d ); an FFT coprocessor for the demodulation of the IOTA signals (314 2 ).
• the DSP associated with a hardware accelerator for modulation, also generates the WCDMA signals to be transmitted in the form of digital samples I and Q (314 3 ).
• the transmission chain comprises: - a digital analog converter 315 1; 315 Q on each of the I and Q channels, with a sampling frequency of 8.192 MHz; an FI 316 modulator controlled by a synthesizer 317; a mixer 318 and an agile synthesizer 319 allowing to 13 transpose the intermediate frequency signals into the transmission band; a power amplifier 36.
• the synchronization of the mobile for the reception of WCDMA signals uses the conventional techniques in this field, and in particular the "Rake filter" for time synchronization.
• this synchronization is used directly for the reception of the IOTA signals, for which no additional synchronization process is required. This directly benefits from the quality and ease of synchronization of the CDMA technique when receiving high-speed data, without adaptation (the frame structures being the same).
• the receiver includes: a low noise amplifier (LNA) 37 j connected to the output 2170-
• LNA low noise amplifier
• the synchronization of the mobile for the reception of WCDMA signals is identical to that described above. Once the reference oscillator and the time base of the moving part are slaved, this initial synchronization is used directly for the reception of the IOTA signals, for which no additional synchronization process is required.

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• Engineering & Computer Science (AREA)
• Signal Processing (AREA)
• Computer Networks & Wireless Communication (AREA)
• Mobile Radio Communication Systems (AREA)

Applications Claiming Priority (3)

Publications (1)

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ID=9525408

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Country Status (6)

Cited By (2)

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• 1998
  • 1998-04-10 FR FR9804883A patent/FR2777407B1/fr not_active Expired - Fee Related
• 1999
  • 1999-04-12 AU AU31529/99A patent/AU3152999A/en not_active Abandoned
  • 1999-04-12 WO PCT/FR1999/000849 patent/WO1999053644A1/fr not_active Ceased
  • 1999-04-12 JP JP2000544090A patent/JP2002511702A/ja active Pending
  • 1999-04-12 US US09/673,114 patent/US6862451B1/en not_active Expired - Fee Related
  • 1999-04-12 EP EP99913390A patent/EP1070401A1/fr not_active Withdrawn
• 2004
  • 2004-09-09 US US10/938,893 patent/US20050136934A1/en not_active Abandoned

Non-Patent Citations (1)

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