EP1520362A1 - Drahtloses audiosignalübertragungsverfahren für ein raumklangsystem - Google Patents
Drahtloses audiosignalübertragungsverfahren für ein raumklangsystemInfo
- Publication number
- EP1520362A1 EP1520362A1 EP03740365A EP03740365A EP1520362A1 EP 1520362 A1 EP1520362 A1 EP 1520362A1 EP 03740365 A EP03740365 A EP 03740365A EP 03740365 A EP03740365 A EP 03740365A EP 1520362 A1 EP1520362 A1 EP 1520362A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- data
- frequency
- audio signal
- signals
- transmitter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Classifications
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04H—BROADCAST COMMUNICATION
- H04H20/00—Arrangements for broadcast or for distribution combined with broadcast
- H04H20/86—Arrangements characterised by the broadcast information itself
- H04H20/88—Stereophonic broadcast systems
Definitions
- the invention relates to a wireless audio signal transmission method for a surround sound system.
- the audio signals are transmitted to up to six different speaker locations. In the living environment, the necessary routing of the signal lines is often problematic. Therefore, wireless transmission is often desired, which also makes it possible to connect players and speakers in different rooms.
- a first step towards improvement is to replace the analog signal transmission with the transmission of data that was formed by prior sampling and digitization of the analog signals.
- the patent application EP 0 082 905 AI shows an example of a wireless audio signal transmission.
- An infrared transmission device is used to transmit digitized audio signals from a transmission device, for example a television receiver, to “active boxes”, which can thus be set up anywhere in the room.
- the annoying signal lines are eliminated and only connections to the usual power network are required for the power supply, which generally do not Unfortunately, this system is only suitable for stereo signals and cannot be used for multi-channel sound processes.
- the object of the invention is to provide a wireless audio signal transmission method and associated transmitting and receiving devices for a multichannel surround sound system, which avoid the disadvantages described above without unreasonably driving up the effort and the audio signal transmission method also for wireless control of headphones, also for stereo operation is suitable.
- the object is achieved according to the features of claim 1 in that the respective audio data for one or more audio signal reproduction devices are first digitized and transmitted as symbols via a digital modulation method.
- the number of high-frequency channels required is based on the bandwidth specified by the respective legislator for each channel and the total bandwidth used
- a suitable diversity process prevents interference caused by multi-path reception and shadowing.
- the propagation of HF and UHF signals within rooms is mainly characterized by a large number of independent propagation paths from the transmitter to the receiver.
- reflections create several indirect paths. Since the path lengths are different, the individual signals meet in different ways
- phase positions to each other If the phase offset is just 0 ° 360 ° or a multiple thereof, one speaks of constructive overlay. But if it is 180 ° or 180 ° plus a multiple of 360 °, it is a destructive overlay. If both signals are of equal strength, the two signal trains are completely canceled in this case. This effect is of course frequency-dependent, since the phase shift depends on the frequency over a fixed path length. Field strength measurements between a transmitter and a receiver, in which there was movement in an interior over a 15 m distance that was provided with reflections and obstacles, resulted in field strength dips of up to 30 dB at a frequency of 864 MHz, although the direct propagation path through an obstacle was dampened.
- the simplest solution would be to increase the transmission power. For legal reasons, this is not possible with the frequencies available. Since the interference effects are dependent on location or route, it makes sense to have two or more independent transmission stretch to realize through a diversity process. The frequency dependence of the interference phenomena can be exploited by simultaneously emitting the signal on two different frequencies and selecting the better signal on the receiver side. This solution is not frequency-efficient and therefore contradicts the objectives of the transmission concept. Receiver diversity is far more widespread. In order to obtain independent paths for the propagation, two receiving antennas are set up at a distance of at least ⁇ / 4 from one another. Now either the stronger antenna signal is selected by the receiver or the two signals are connected together. In order to avoid failures when switching over, however, this presupposes that at each receiver location at least two receivers are completely available until the channel-coded data is recovered.
- FIG. 1 schematically shows the known transmitter and receiver diversity
- FIG. 2 shows schematically the known transmitter diversity
- FIG. 5 shows the transmission scheme with the associated “space-time block code”
- FIG. 6 shows schematically as a block diagram a transmitter according to the invention
- Fig. 7 shows schematically a block diagram of a receiver according to the invention
- each transmitter and one receiver is usually required for each transmission channel, cf. Fig. 1. If, in the simplest case, each audio channel is designed twice, this results in 12 high-frequency channels and for the six speaker locations as many transmitters, receivers and antennas. That would make an economical implementation impossible.
- FIG. 1 shows an example of such a diversity with two channels, in which a signal source Q with a reproduction device LB, for example a loudspeaker box, via two transmitters S1, S2 with two antennas AS1, AS2 and two receivers El, E2 with two antennas AE1 , AE2 is connected, the signals emitted via the transmission antennas AS1, AS2 having different transmission frequencies fl, f2.
- the received signals are evaluated and the actual audio signals are generated in downstream electronics E3. Due to the frequency-dependent propagation conditions of the two transmission frequencies fl, f2, diversity is already achieved because the phase positions differ in the case of reflections and obstacles and attenuation or even extinction generally takes place at different frequencies, so that one of the received signals always has sufficient field strength.
- a one-sided diversity procedure represents a simplification in the effort, which is either only on the transmitter side, cf. Fig. 2, or only on the receiver side, cf. Fig. 3, have separate transmission or reception channels, which on the other side is opposed to a single receiver E4 or transmitter S3.
- the signals to be transmitted are transmitted by means of two transmitters S 1 and S2 and two antennas AS 1 and AS2 on two different frequencies fl, f2.
- the signals running over the different propagation paths overlap and are recorded by means of a single antenna AE with the associated receiver E4.
- the transit time differences as a result of the frequency and spatial diversity generally prevent total extinction at both frequencies fl, f2 at the same time. in the
- Receiver E4 is either superimposed on the signal content of both frequencies fl, f2 or the frequency selected which currently has the higher field strength.
- FIG. 2 which is however not shown, uses the same transmitting antenna for both frequencies fl, f2. In this case there is only frequency diversity.
- the receiver diversity according to FIG. 3 there is only a single transmitter S3 which radiates the signal with the transmission frequency f via its antenna AS.
- this signal is received with two separate antennas AE1, AE2 and associated receivers El, E2, which, as in FIG. 1, are followed by common electronics E3, which ultimately feeds the playback device LB.
- This method is space diversity, and directional or polarity diversity can be added by means of the receiving antennas AE1, AE2.
- Either the two signals of the receivers E1, E2 are superimposed in the downstream electronics E3 or this has a selection circuit which only processes the antenna signal with the higher field strength.
- Receiver diversity is often used in the professional field for portable microphones, for example, because there are no transmit antennas at all.
- the frequency-modulated signal from the microphone transmitter is received by an associated receiving device, which is coupled to two extendable antennas; which are each connected to a radio frequency receiver.
- the diversity process is not optimal because of the relatively small distance between the receiving antennas, but in the professional field the electronic effort with sensitive receivers, the forwarding and processing of the signals is of course not important; if necessary, another receiving device is used.
- Naguib, Nambi Seshadri and AR Calderbank are described in detail for different variants.
- the source Q In order to be able to apply this method to the control of high-quality audio reproduction devices LB, the source Q must supply data as audio signals or it must in the case analog signals, digitization takes place in the source Q or in a downstream encoder CS.
- the data stream D 0 to be transmitted is processed in the encoder CS according to FIG. 5 into a first and second data stream Di, D 2 , which is supplied to the transmitting stage S4 with two high-frequency transmitters S5, S6 and via two spatially separated antennas AS1, AS2 broadcast as quadrature modulated signals, but despite different contents in the same frequency band f.
- a single high-frequency receiving device AE, E5 with a correspondingly adapted decoding device CE is sufficient in the receiving device E50 in order to recover the original data sequence D 0 from the superimposed signals r or a data sequence Dr formed therefrom. This is then available for further processing and playback in the audio playback device LB. It is not a disadvantage that this diversity method can only be applied to the transmission of data, as is well known, because the transmission of data is known to be less susceptible to interference than the transmission of analog signals and, with suitable coding, also requires less channel width. If that
- the audio signal is converted into a data stream by digitization, known methods of data compression can also be used.
- a further simplification is achieved by data compression on the transmitter side.
- the available high-frequency channels are relatively narrow-band and only have a maximum
- Channel width of, for example, 300 kHz.
- data compression enables you to transmit data from two or more audio channels on one high-frequency channel.
- the data compression takes advantage of the redundancy of audio signals, the right and left information of symmetrical loudspeaker locations generally being particularly suitable for such compression.
- the data stream is then converted into symbols which are transmitted by means of the high-frequency carrier.
- the intended digital transmission ie the transmission with symbols, requires an evaluation of the received signal on the receiver side at predetermined times at which the transmitted signal assumes a defined state in the quadrature signal level. To determine this state, which corresponds to the transmitted digital symbol but is more or less disturbed due to the transmission, the received signal is sampled and digitized at least at defined times.
- the interference clearance, further implementation and decoding are then also carried out purely digitally. With zero IF or low IF receivers where The two quadrature components can be converted directly into the baseband or a low frequency range and digitized there, particularly inexpensive reception concepts can be specified, which can be accommodated in a single IC for each receiver and do not require any significant external circuitry.
- Some high-frequency bands are available for the selection of the transmission band.
- a transmission band which is free for such transmissions is expediently taken.
- the released frequency range between 433.020 MHz and 434.790 MHz, which is also known as the "ISM band", is less suitable because there is no protection from other users and the privileged transmissions of the amateur radio service. It does not only interfere with your own alarm system or the Radio-controlled central locking of the neighbor's car.
- the FM signal can also be listened to by anyone. The one withheld for audio transmissions
- Frequency bands from 863 MHz to 865 MHz have so far been accepted with great hesitation, presumably because the permissible transmission power with 10 mW radiation power (ERP) is relatively low for operation without individual permits.
- ERP mW radiation power
- the use of this frequency band would be quite suitable for wireless control of the audio playback devices, as long as the transmitting and receiving antennas have a view of one another. If this is not the case, reception will be impaired.
- the signal is not only attenuated, but also reflected many times. If two of these signal components arrive at the receiver in opposite phase and approximately equally strong, they cancel each other out. This is called interference. In extreme cases, an almost total loss of reception can result.
- Delay is too great and a pre-delay of the picture information in the home area on the transmitter side is too complex.
- 16-QAM is expediently chosen as the digital modulation for the transmission of the symbols. This represents a favorable compromise between the transmission capacity and the feasibility. Extensive system analyzes show that a 3/4 trellis coding of the modulation ensures adequate error protection.
- the gross data rate for the stereo signal is then 768 kB / s.
- the synchronization and the control of the spatially distributed audio playback devices require a small number of additional data to be transmitted, so that the final data rate is approximately 840 kB / s.
- the symbol rate of 210 kS / s thus obtained can be accommodated with a roll-off factor of 19% in a 250 kHz wide channel. This means that eight HF carriers with two audio channels each are available in the 2 MHz wide segment between 863 MHz and 865 MHz.
- a fully developed system with 6-channel sound requires 3 of the 8 RF channels, so that only 2 such systems can be operated side by side in the house without interfering with each other.
- Experience shows, however, that often the center and sub loudspeakers are connected directly to the playback device via wire, which means that only 2 RF channels are required.
- the system provides for a dynamic allocation of the channels, which means that only one carrier has to be used for a stereo signal, for example, even if more than 2 speakers are addressed.
- the fundamental consideration that two antennas set up sufficiently far apart from one another on at least one side of the transmission path with a single antenna on the opposite side form two independent transmission links also applies in the event that the two antennas are located on the transmitter side.
- the table in FIG. 5 schematically shows the STBC coding and transmission of a data sequence D 0 with the data, A, B, C, D.
- the first line “clock” gives the successive clocks Ti, T 2 , T 3 , T 4 for the original data sequence D 0 and the transmission of symbols
- Data sequence D 0 with the data A, B, C, D is on the second line.
- the third and fourth lines show a first data sequence Di obtained by transformation with the data A, -B *, C, -D *, D2 and a second data sequence D 2 with the data B, A *, D, C *.
- the third and fourth lines represent the symbol sequences which are transmitted by the two antennas AS 1 and AS2 by means of quadrature signals.
- the asterisk "*" indicates the conjugate complex data value.
- the fifth line defines the even and odd times "even” and "odd” with respect to the clocks Ti to T 4.
- the sixth line finally shows the summary of the symbols A, B and C, D to a first or second pair of symbols Syl, Sy 2.
- the data sequences Di, D 2 can also be composed differently, for example D t with A, B *, C, D * and D 2 with -B, A *, -D, A * or other combinations, it only has to be ensured that the symbols A, B, C, D are coded differently in both data sequences and that the corresponding equations are available on the receiving side.
- the two successive symbols A, B are transmitted in parallel.
- the antenna AS1 transmits the symbol A and the antenna transmits the symbol B.
- the two symbols A, B transmitted first are interchanged and transformed, so that in the second step during the cycle T 2 on the antenna AS1, the symbol B conjugates complex and negates as -B * and the other symbol A conjugates complexly as A. * is transmitted.
- hl means the transfer function from the first antenna AS1 to the receiving antenna AE and h2 the transfer function from the second antenna AS2 to the receiving antenna AE.
- the received signal size at the time “even” is r CT and is composed of the components A and B and the two transfer functions hl and h2.
- the received signal size r odd at the time “odd” is made up of the components hl, h2, A * and -B * together. If the transfer functions h1 and h2 are known, equations (1) and (2) represent a linear system from which A and B can be determined. If the conjugate complex form is formed according to equation (3) from both sides of equation (2), then the symbols A, B are identical to the symbols of equation (1).
- the transfer functions h1, h2 are initially unknown. However, they represent a steady state, as it were, because the room conditions change relatively slowly compared to the data rate. It can also be assumed from the expedient assumption that both transmission functions are initially the same and then seek the optimal setting by means of a control process on the receiver side. For this purpose, the received signals are multiplied on the receiver side by an inverse transfer function in a linear combination h "1 (see FIG. 7), which is initially available as an estimate and is adapted by an adaptive algorithm to the actual transfer functions of the two transmit antennas AS 1, AS2
- the transfer functions hl or h2 and their associated inverse transfer functions hf 'or h 2 " ' in the linear combination h " 1 together form a linear frequency response.
- the linear combination h "1 means that the symbols A ', B' received after the transfer converted into the quadrature signal level in such a way that the associated decided symbols A “, B” can be determined from these values by means of a symbol decision maker ET.
- Kicking through changes in the received symbols A ', B' deviations from the inverse transfer functions hf ', h 2 "2 in the linear combination h " 1 then these deviations are recorded as differences using a system of equations in a computing unit RE.
- These difference values are smoothed by means of a control loop filter Fr and supplied to the linear combination h "1 as correction values.
- FIG. 6 shows the essential functional units of an exemplary embodiment of a transmission device S40 according to the invention as a block diagram.
- a signal source Q supplies an analog audio signal to an analog-digital converter AD, the output of which delivers a data stream D 0 with the symbol rate specified by the digitization clock ts.
- the digitization clock expediently corresponds to the symbol clock t s generated in a symbol clock generator T s or a multiple thereof.
- the two different data streams Di and D 2 are formed from the data stream D, which the individual pairs of symbols A, B; C, D included, but according to FIG. 5, each with different codings in the quadrature signal level.
- a high-frequency stage S4 the two data sequences Di, D 2 are transmitted into the desired high-frequency band f by means of two quadrature mixers Ml, M2 and by means of the sine and cosine components of a quadrature carrier tr originating from a high-frequency oscillator Osl and are transmitted separately via the antennas AS1, AS2.
- the required pulse shape filters and the filter devices for avoiding interference and alias signals are not shown in FIG. 6 for the sake of a better overview.
- Fig. 7 shows schematically as a block diagram an embodiment for a receiving device E50 according to the invention.
- the circuit block E5 is a superimposed receiver which converts the high-frequency signal received via the antenna AE from the high-frequency channel f into an intermediate frequency position using a high-frequency mixer M3, which is approximately in a frequency range from 1 to 2 MHz.
- the carrier for the mixer M3 is a high-frequency signal HF from a local oscillator Os2.
- a bandpass filter Fld filters out the desired frequency band and feeds the filtered signal to an analog-digital converter ADE for digitization.
- the conversion into an intermediate frequency has the advantage that only a single analog-digital converter ADE is required.
- zero-IF or low-IF conversion is split into two channels which are quadrature with respect to one another and which therefore also require two analog-digital converters.
- the further processing in the decoding device CE is carried out purely digitally, regardless of the preceding stage E5.
- the digitized signal after the analog-digital converter ADE is now converted by means of a quadrature mixer M4 and decimation stages (not shown) in such a way that the data rate of the resulting data stream corresponds to the symbol rate t s or an integer multiple thereof.
- the quadrature mixer M4 is fed by an oscillator Os3 with a sine and cosine component of the downmixed carrier frequency, which also result in two mixture components at the output of the mixer M4.
- the data lines for these two components are shown as double lines in FIG. 7. If the preceding circuit block E5 is a zero-IF or a low-IF converter, then there are already two data paths in quadrature in the low frequency range and the quadrature mixer M4 is omitted.
- the components in the two data lines are digitized signal values, which, however, are linked to the symbols transmitted.
- An electronic switch Swl now distributes these digital values in synchronism with the symbol clock t s to two switch outputs 1, 2 and thus feeds the inputs of a symbol recognition device SD.
- the signals from the mixer M4 are alternately divided between the two inputs 1, 2 of the symbol recognition device SD, at the output of which the decided symbols can be tapped from the received signal.
- Linear combination h "1 have the provisionally estimated symbols A ', B' and C, D 'available at each of their two outputs from each symbol pair Syl, Sy2.
- a decision maker ET uses this to form the decided symbols A", B “or C”"D", which are converted into electronic data for the symbols A, B, C, D for further processing by means of a subordinate table TB.
- the symbols A, B and C, D of the symbol pairs appearing in parallel form an alternating with the symbol cycle ts controlled switch Sw2 again the original data sequence D 0 with the data A, B, C, D. This data stream can be converted into the desired audio signal.
- the carrier is placed in an active frequency band when mixing. This creates a large DC component in the downmixed signal, which usually exceeds the working range of the analog-digital converter. If the signal size is reduced, the resolution is lost. It is therefore sensible to take a different path, by means of a simple one Control loop is superimposed on the analog signal before digitization, a sufficiently large equivalent value until the signal is reasonably in the modulation range of the analog or digital converter.
- the parameters in the linear combination h "1 are adjusted by comparing the signals from the inputs 1, 2 and the two outputs of the symbol decision maker ET to one input of the computing unit RE.
- Deviations in the linearity are in the
- Computing unit RE is determined by means of its equation systems and generates correction signals which are fed to the linear combination h "1 via a control loop filter for correction inputs.
- Audio playback device is dependent. Further control information relates to the location of the device within the surround sound system, i.e. its address, the data compression method used, information about the current protective measures for data backup during transmission and synchronization bits for recognizing the start of the data packet and for synchronizing the symbol recognition. Such control information must be inaudibly superimposed on the actual audio signal or additionally transmitted.
- the packet format for transmission which contains all the necessary control information and addresses in a header, is expediently appropriate here.
- the actual data part then contains the data for the audio signal, possibly also test bits or empty bits, in order to fill in the individual data areas.
- the selected uniform data packet structure is expediently 10 ms long.
- Both data formats each represent a data packet FD with a length of 10 ms.
- the upper data format is particularly suitable for a source rate of 48 kHz and the lower one for a source rate of 44.1 kHz.
- the header data area H is followed alternately by the individual data blocks for the left and right audio channels L and R.
- the compression is based on these blocks in pairs, so that the decompression (see arrows "Decomp.” In FIG. 8) on the receiver side after reception of the first pair of audio blocks L, R.
Abstract
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE10229266 | 2002-06-28 | ||
DE10229266 | 2002-06-28 | ||
PCT/EP2003/006816 WO2004004178A1 (de) | 2002-06-28 | 2003-06-27 | Drahtloses audiosignalübertragungsverfahren für ein raumklangsystem |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1520362A1 true EP1520362A1 (de) | 2005-04-06 |
Family
ID=29796007
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP03740365A Withdrawn EP1520362A1 (de) | 2002-06-28 | 2003-06-27 | Drahtloses audiosignalübertragungsverfahren für ein raumklangsystem |
Country Status (4)
Country | Link |
---|---|
US (1) | US20060153389A1 (de) |
EP (1) | EP1520362A1 (de) |
JP (1) | JP2005531955A (de) |
WO (1) | WO2004004178A1 (de) |
Families Citing this family (14)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE102004017215A1 (de) * | 2004-04-05 | 2005-10-20 | Sennheiser Electronic | Audiovisuelles System |
US20060009985A1 (en) * | 2004-06-16 | 2006-01-12 | Samsung Electronics Co., Ltd. | Multi-channel audio system |
JP2006101496A (ja) | 2004-09-02 | 2006-04-13 | Mitsubishi Materials Corp | オーディオ・ビジュアルデータ通信システム、オーディオ・ビジュアルデータ送信装置及びオーディオ・ビジュアルデータ再生装置 |
KR100913873B1 (ko) * | 2004-09-13 | 2009-08-26 | 삼성전자주식회사 | 고속 전송률을 가지는 차등 시공간 블록 부호 장치 및 방법 |
US8050203B2 (en) | 2004-12-22 | 2011-11-01 | Eleven Engineering Inc. | Multi-channel digital wireless audio system |
WO2007019861A2 (en) | 2005-08-16 | 2007-02-22 | Play It Sound Aps | Playground device with motion dependent sound feedback |
US8249527B2 (en) * | 2006-02-09 | 2012-08-21 | Vixs Systems, Inc. | Multimedia client/server system, client module, multimedia server, radio receiver and methods for use therewith |
US8355715B2 (en) * | 2006-04-21 | 2013-01-15 | Vixs Systems, Inc. | Client module, multimedia server and methods for use therewith |
US20090007194A1 (en) * | 2007-04-30 | 2009-01-01 | Thales Avionics, Inc. | Remote recovery of in-flight entertainment video seat back display audio |
DE102010038838A1 (de) * | 2010-08-03 | 2012-02-09 | Sennheiser Electronic Gmbh & Co. Kg | Audio- und/oder Videoübertragungssystem |
RU2011121330A (ru) * | 2011-05-27 | 2012-12-10 | Михаил Леонидович Любачев | Мобильное звуковоспроизводящее устройство |
US9094761B2 (en) * | 2011-12-15 | 2015-07-28 | Panasonic Automotive Systems Company Of America, Division Of Panasonic Corporation Of North America | Digital technique for FM modulation of infrared headphone interface signals |
KR102406695B1 (ko) * | 2015-12-24 | 2022-06-08 | 삼성전자주식회사 | 무선 통신 시스템에서 사운드 신호를 기반으로 데이터를 송신 및 수신하는 장치 및 방법 |
WO2017164156A1 (ja) * | 2016-03-22 | 2017-09-28 | ヤマハ株式会社 | 信号処理装置、音響信号の転送方法、及び、信号処理システム |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0082905B1 (de) * | 1981-12-24 | 1986-04-09 | Deutsche ITT Industries GmbH | Schaltungsanordnung zur Verarbeitung, Übertragung und akustischen Wiedergabe von digitalisierten Tonfrequenzsignalen |
IL100213A (en) * | 1990-12-07 | 1995-03-30 | Qualcomm Inc | Mikrata Kedma phone system and its antenna distribution system |
FR2696064B1 (fr) * | 1992-09-18 | 1994-11-18 | France Telecom | Système de diffusion de signaux numériques à génération active de la diversité en temps, émetteur et récepteur correspondants. |
US5812935A (en) * | 1993-04-17 | 1998-09-22 | Hughes Electronics | Cellular system employing base station transmit diversity according to transmission quality level |
JPH07131858A (ja) * | 1993-10-29 | 1995-05-19 | Hitachi Denshi Ltd | 1周波同時送受話方式無線機のdtmf信号伝送方式 |
US6178317B1 (en) * | 1997-10-09 | 2001-01-23 | Ibiquity Digital Corporation | System and method for mitigating intermittent interruptions in an audio radio broadcast system |
WO2000033474A1 (en) * | 1998-11-30 | 2000-06-08 | Phonex Corporation | Multi-channel wireless speaker system using multiplexed channel combining and frequency diversity |
US7088785B2 (en) * | 1998-12-31 | 2006-08-08 | Texas Instruments Incorporated | Block level space time transmit diversity in wireless communications |
US6760323B1 (en) * | 1999-02-04 | 2004-07-06 | Concerto Software, Inc. | System and method for providing audio communication over a computer network using differing communication formats |
US6356528B1 (en) * | 1999-04-15 | 2002-03-12 | Qualcomm Incorporated | Interleaver and deinterleaver for use in a diversity transmission communication system |
US7020072B1 (en) * | 2000-05-09 | 2006-03-28 | Lucent Technologies, Inc. | Orthogonal frequency division multiplexing transmit diversity system for frequency-selective fading channels |
GB0102261D0 (en) * | 2001-01-29 | 2001-03-14 | Vtech Communications Ltd | Enhanced cordless telephone platform using bluetooth technology |
US6885987B2 (en) * | 2001-02-09 | 2005-04-26 | Fastmobile, Inc. | Method and apparatus for encoding and decoding pause information |
-
2003
- 2003-06-27 WO PCT/EP2003/006816 patent/WO2004004178A1/de active Application Filing
- 2003-06-27 JP JP2004516718A patent/JP2005531955A/ja active Pending
- 2003-06-27 US US10/519,590 patent/US20060153389A1/en not_active Abandoned
- 2003-06-27 EP EP03740365A patent/EP1520362A1/de not_active Withdrawn
Non-Patent Citations (1)
Title |
---|
See references of WO2004004178A1 * |
Also Published As
Publication number | Publication date |
---|---|
US20060153389A1 (en) | 2006-07-13 |
WO2004004178A1 (de) | 2004-01-08 |
JP2005531955A (ja) | 2005-10-20 |
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