(12) Unlted States Patent
`(10) Patent N0.:
`US 7,412,294 B1
`
`Woolfork
`(45) Date of Patent:
`Aug. 12, 2008
`
`USOO7412294B1
`
`(54) WIRELESS DIGITAL AUDIO SYSTEM
`
`(76)
`
`Inventor: C. Earl Woolfork, 500 Santa Paula Ave.,
`Pasadena, CA (US) 91 107
`
`( * ) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 199 days.
`
`(21) Appl. No; 10/648 012
`3
`-
`.
`(22) Ffled'
`
`Aug. 26’ 2003
`
`.
`.
`Relamd U'S' Applicatlon Data
`(63) Continuation-impart of application No. 10/027,391,
`filed on Dec. 21 2001, now abandoned.
`’
`
`(51)
`
`Int. C1.
`(2006.01)
`G06F 17/00
`(2008.01)
`H04H 40/00
`(52) US. C1.
`........................................ 700/94- 455/306
`(58) Field of Classification Search ................... 700/94;
`714/709, 780, 795: 7945 75; 706/8, 9; 455/306,
`455/41, 66.1, 41.3, 564.1, 412, 413; 375/224,
`375/2954297, 346, 348, 219, 341, 140, 147,
`375/146’ 130’ 340’ 316’ 1438éf§72§2$3323é
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`References Cited
`fi
`U.S. PATJNT DOCUMENTS
`5 491 839 A 4
`2/ 996 Schotz .....
`455/39
`5:771:441 A 4
`6/ 998 Altstatt .....
`.. 455/661
`
`5,790,595 A 4
`3/ 998 Benthin et a1.
`375/224
`5,946,343 A 4
`g/ 999 Schotz et 31.
`............... 375/141
`6,342,844 B1 4 wow Rozin ....................... 340/933
`6,418,558 B1 *
`7/2002 Roberts et al.
`725/129
`
`................. 725/75
`6,678,892 B1>X<
`1/2004 I_avelle et al.
`6,982,132 B1 *
`1/2006 Goldner et al.
`............. 429/162
`
`S
`
`(56)
`
`
`
`............... 455/41
`3/2003 Mooney et a1.
`2003/0045235 A1*
`2004/0223622 A1* 11/2004 Lindemann et al.
`........... 381/79
`
`44
`
`OTHDR PUBLICATIONS
`Specification of the Bluetooth System. Version 1.0 B, pp. 17-27,
`4144. 81-86, 143-147.*
`Pohlrnan, K. C. Principles of Digital Audio. McGraW-Hill, Inc., 3rd
`ed 19951311 155-15”
`SAA7360 Bitstream conversion ADC for digital audio systems.
`
`Datasheet [online]. Philips Semiconductors, 1995 [retrieved on Dec.
`15, 2005]. Retrieved from the Internet: <URL: http://wwwortodox-
`ism.ro/datasheets/philips/SAA7360GP.pdf>.*
`Wikipedacom entry for Viterbi Decoder.*
`wikipediacom entry for Viterbi Algorithm.*
`A Tutorial on Convolutional Coding with Viterbi Decoding; Chip
`Flemmg~*
`wwwtelecomspacecom overview for CDMA.*
`“Digital Communication Techniques” by Simon. Hinedi and
`Lindsey
`
`(Continued)
`
`Primary Exam/Wismn Ni
`Ammm Examl’zeriAndFew C Flanders
`(74) Attorney, Agent, or FirmiMegan E. Lyman
`
`ABSTRACT
`(57)
`A Wireless digital audio system includes a portable audio
`source with a digital audio transmitter operatively coupled
`thereto and an audio receiver operatively coupled to a head-
`phone set. The audio receiver is configured for digital Wire-
`less communication with the audio transmitter. The digital
`audio receiver utilizes fuzzy logic to optimize digital signal
`processing. Each ofthe digital audio transmitter andreceiver
`is configuredforcode divisionmultipleaccess (CDMA) com-
`munication. The Wireless digital audio system allows private
`audio enjoyment Without interference from other users of
`independent wireless digital transmitters and receivers shar-
`111% the same Space
`
`19 Claims, 3 Drawing Sheets
`
`
`
`SONY Exhibit 1006 - 0001
`
`SONY Exhibit 1006 - 0001
`
`

`

`US 7,412,294 B1
`
`Page 2
`
`OTHER PUBLICATIONS
`
`“Wireless Communications” by Rappaport.
`“Communication Networks” by Walrand,
`
`“Unified Analysis of Certain Coherent and Noncoherent Binary
`Communications Systems” by Stein in IEEE Transactions on Infor-
`mation Therory. Jan, 1964.
`* Cited by examiner
`
`SONY Exhibit 1006 - 0002
`
`SONY Exhibit 1006 - 0002
`
`

`

`U.S. Patent
`
`Aug. 12, 2008
`
`Sheet 1 013
`
`us 7,412,294 B1
`
`
`
`FIG.1
`
`SONY Exhibit 1006 - 0003
`
`SONY Exhibit 1006 - 0003
`
`

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`
`

`

`1
`WIRELESS DIGITAL AUDIO SYSTEM
`
`2
`BRIEF DESCRIPTION OF THF DRAWINGS
`
`US 7,412,294 B1
`
`This utility patent application is a continuation-in-part of
`US. patent application Ser. No. 10/027,391, filed Dec. 21,
`2001, now abandoned for “Wireless Digital Audio System,”
`published under US 2003/0118196 Al on Jun. 26, 2003, now
`abandoned, which is incorporated herein in its entirety by
`reference.
`
`BACKGROUND OF THE INVENTION
`
`This invention relates to music audio player devices and
`more particularly to systems that include headphone listening
`devices. The new audio music system uses an existing head-
`phone jack (i.e., this is the standard analog headphone jack
`that connects to wired headphones) of a music audio player
`(i.e., portable CD player, portable cassette player, portable
`A.M./F.M. radio,
`laptop/desktop computer, portable MP3
`player, and the like) to connect a battery powered transmitter
`for digital wireless transmission of a signal to a set of battery
`powered receiver headphones.
`Use of music audio headphones with music audio player
`devices such as portable CD players, portable cassette play-
`ers, portable A.M./F.M. radios,
`laptop/desktop computer,
`portable MP3 players and the like, have been in use for many
`years. These systems incorporate an audio source having an
`analog headphone jack to which headphones may be con-
`nected by wire.
`There are also known wireless headphones that may
`receive A.M. and FM. radio transmissions. However, they do
`not allow use of a simple plug in (i.e., plug in to the existing
`analog audio headphonejack) battery powered transmitter for
`connection to any music audio player device jack, such as the
`above mentioned music audio player devices, for coded wire-
`less transmission and reception by headphones of audio
`music for private listening without interference where mul-
`tiple users occupying the same space are operating wireless
`transmission devices. Existing audio systems make use of
`electrical wire connections between the audio source and the
`
`headphones to accomplish private listening to multiple users.
`There is a need for a battery powered simple connection
`system for existing music audio player devices (i.e., the pre-
`viously mentioned music devices), to allow coded digital
`wireless transmission (using a battery powered transmitter) to
`a headphone receiver (using battery powered receiver head-
`phones) that accornplishes private listening to multiple users
`occupying the same space without the use of wires.
`SUMMARY OF THE INVENTION
`
`The present invention is generally directed to a wireless
`digital audio system for coded digital transmission of an
`audio signal from any audio player with an analog headphone
`jack to a receiver headphone located away from the audio
`player. Fuzzy logic technology may be utilized by the system
`to enhance bil detection. A battery-powered digital transmit-
`ter may include a headphone plug in communication with any
`suitable music audio source. Forreception, a battery-powered
`headphone receiver may use embedded fuzzy logic to
`enhance user code bit detection. Fuzzy logic detection may be
`used to enhance user code bit detection during decoding ofthe
`transmitted audio signal. The wireless digital audio music
`system provides private listening without interference from
`other users or wireless devices and without the use of con-
`ventional cable comrections.
`
`These and other features, aspects and advantages of the
`present invention will become better understood with refer-
`ence to the following drawings, description and claims.
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`Some aspects of the present invention are generally shown
`by way ofreference to the accompanying drawings in which:
`FIG. 1 schematically illustrates a wireless digital audio
`system in accordance with the present invention;
`FIG. 2 is a block diagram ofan audio transmitterportion of
`the wireless digital audio system of FIG. 1;
`FIG. 3 is a block diagram of an audio receiverportion ofthe
`wireless digital audio system of FIG. 1; and
`FIG. 4 is an exemplary graph showing the utilization of an
`embedded fuzzy logic coding algorithm according to one
`embodiment of the present invention.
`
`DETAILED DESCRIPTION
`
`The following detailed description is the best currently
`contemplated modes for carrying out the invention. The
`description is not to be taken in a limiting sense, but is made
`merely for the purpose of illustrating the general principles of
`the invention.
`
`Referring to FIGS. 1 through 3, a wireless digital audio
`music system 10 may include a battery powered transmitter
`20 connected to a portable music audio player or music audio
`source 80. The battery powered wireless digital audio music
`transmitter 20 utilizes an analog to digital converter or ADC
`32 and may be comrected to the music audio source 80 analog
`headphone jack 82 using a headphone plug 22. The battery
`powered transmitter 20 may have a transmitting antenna 24
`that may be omni-directional for transmitting a spread spec-
`trum modulated signal to a receiving antenna 52 of a battery
`powered headphone receiver 50. The battery powered
`receiver 50 may have headphone speakers 75 in headphones
`55 for listening to the spread spectrum demodulated and
`decoded communication signal. In the headphone receiver
`50, fuzzy logic detection may be used to optimize reception of
`the received user code. The transmitter 20 may digitize the
`audio signal using ADC 32. The digitized signal may be
`processed downstream by an encoder 36. After digital con-
`version, the digital signal may be processed by a digital low
`pass filter. To reduce the effects of channel noise, the battery
`powered transmitter 20 may use a channel encoder 38. A
`modulator 42 modulates the digital signal to be transmitted.
`For further noise immunity, a spread spectrum DPSK (differ-
`ential phase shift key) transmitter or module 48 is utilized.
`The battery powered transmitter 20 may contain a code gen-
`erator 44 that may be used to create a unique user code. The
`unique user code generated is specifically associated with one
`wireless digital audio system user, and it is the only code
`recognized by the battery powered headphone receiver 50
`operated by a particular user. The radio frequency (RF) spec-
`trum utilized (as taken from the Industrial, Scientifc and
`Medical (ISM) band) may be approximately 2.4 GHz. The
`power radiated by the transmitter adheres to the ISIV stan-
`dard.
`
`
`
`Particularly, the received spread spectrum signal may be
`communicated to a 2.4 GHz direct conversion receiver or
`
`module 56. Referring to FIGS. 1 through 4, the spreac spec-
`trum modulated signal from transmit antenna 24
`ay be
`received by receiving antenna 52 and then processed by
`spread spectrum direct conversion receiver or module 56 with
`a receiver code generator 60 that contains the same tra ismit-
`ted unique code, in the battery powered receiver 50 head-
`phones. The transmitted signal from antenna 24
`ay be
`received by receiving antenna 52 and communicated to a
`wideband bandpass filter
`(BPF). The battery powered
`receiver 50 may utilize embedded fuzzy logic 61 (as graphi-
`
`SONY Exhibit 1006 - 0006
`
`SONY Exhibit 1006 - 0006
`
`

`

`US 7,412,294 B1
`
`3
`cally depicted in FIGS. 1, 4) to optimize the bit detection of
`the received user code. The down converted output signal of
`direct conversion receiver or module 56 may be summed by
`receiver summing element 58 with a receiver code generator
`60 signal. The receiver code generator 60 may contain the
`same unique wireless transmission of a signal code word that
`was transmitted by audio transmitter 20 specific to a particu-
`lar user. Other code words from wireless digital audio sys-
`tems 10 may appear as noise to audio receiver 50. This may
`also be true for other device transmitted wireless signals
`operating in the wireless digital audio spectrum of digital
`audio system 10. This code division multiple access (CDMA)
`may be used to provide each user independent audible enj oy-
`ment. The resulting summed digital signal from receiving
`summary element 58 and direct conversion receiver or mod-
`ule 56 may be processed by a 64-Ary demodulator 62 to
`demodulate the signal elements modulated in the audio trans-
`mitter 20. A block de-interleaver 64 may then decode the bits
`of the digital signal encoded in the block interleaver 40.
`Following such, a Viterbi decoder 66 may be used to decode
`the bits encoded by the channel encoder 38 in audio transmit-
`ter 20. A source decoder 68 may fitrther decode the coding
`applied by encoder 36.
`Each receiver headphone 50 user may be able to listen
`(privately) to high fidelity audio music, using any ofthe audio
`devices listed previously, without the use of wires, and with-
`out interference from any other receiver headphone 50 user,
`even when operated within a shared space. The fuzzy logic
`detection technique 61 used in the receiver 50 could provide
`greater user separation through optimizing code division in
`the headphone receiver.
`The battery powered transmitter 20 sends the audio music
`information to the battery powered receiver 50 in digital
`packet fonnat. These packets may flow to create a digital bit
`stream rate of less than or equal to 1.0 Mbps.
`"he user code bits in each packet may also be received and
`detected by a fuzzy logic detection sub-system 61 (as an
`option) embedded in headphone receiver 50 to optimize audio
`receiver performance. For each consecutive packet received,
`fuzzy logic detection sub-system 61 may compute a condi-
`tional density with respect to the context and fuzziness of the
`user code vector, i.e., the received code bits in each packet.
`Fuzziness may describe the ambiguity of the high bit (1)/low
`bit (0 or — 1) event in the received user code within the packet.
`The fuzzy logic detection sub-system 61 may measure the
`degree to which a high’low bit occurs in the user code vector,
`which produces a low probability of bit error in the presence
`of noise. The fuzzy logic detection sub-system 61 may use a
`set of if—then rules to map the user code bit inputs to validation
`outputs. These rules may be developed as if-then statements.
`Fuzzy logic detection sub-system 61 in battery-powered
`headphone receiver 50 utilizes the if-then fuzzy set to map the
`received user code bits into two values: a low (0 or — 1) and a
`high (1). Thus, as the user code bits are received, the “if” rules
`map the signal bit energy to the fuzzy set low value to some
`degree and to the fuzzy set high value to some degree. FIG. 4
`graphically shows that x-value —1 equals the maximum low
`bit energy representation and x-value 1 equals the maximum
`high bit energy representation. Due to additive noise, the user
`code bit energy may have some membership to low and high
`as represented in FIG. 4. The if-part fuzzy set may determine
`if each bit in the user code, for every received packet, has a
`greater membership to a high bit representation or a low bit
`representation. The more a user code bit energy fits into the
`high or low representation, the closer its subsethood, i.e., a
`measure of the membership degree to which a set may be a
`subset of another set, may be to one.
`
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`The if—then rule parts that make up the fuzzy logic detection
`sub-system 61 must be followed by a defuzzifying operation.
`This operation reduces the aforementioned fuzzy set to a bit
`energy representation (i.e., —1 or 1) that is received by the
`transmittedpacket. Fuzzy logic detection sub-system 61 may
`be used in battery-powered headphone receiver 50 to enhance
`overall system performance.
`The next step may process the digital signal to return the
`signal to analog or base band fomiat for use in powering
`sneaker(s) 75. A digital-to-analog converter 70 (DAC) may be
`used to transform the digital signal to an analog audio signal.
`An analog low pass filter 72 may be used to filter the analog
`audio music signal to pass a signal in the approximate 20 Hz
`to 20 kHz frequency range and filter other frequencies. The
`analog audio music signal may then be processed by a power
`amplifier 74 that may be optimized for powering headphone
`speakers 75 to provide a high quality, low distortion audio
`music signal for audible enjoyment by a user wearing head-
`phones 55. A person skilled in the art would appreciate that
`some of the embodiments described hereinabove are merely
`illustrative of the general principles of the present invention.
`Other modifications or variations may be employed that are
`within the scope of the invention. Thus, by way of example,
`but not of limitation, alternative configurations may be uti-
`lized in accordance with the teachings herein. Accordingly,
`the drawings and description are illustrative and not meant to
`be a limitation thereof.
`
`Moreover, all terms should be interpreted in the broadest
`possible manner consistent with the context. In particular, the
`terms “comprises” and “comprising” should be interpreted as
`referring to elements, components, or steps in a non—exclusive
`manner, indicating that the referenced elements, components,
`or steps may be present, or utilized, or combined with other
`elements, components, or steps that are not expressly refer-
`enced. Thus, it is intended that the invention cover all embodi-
`ments and variations thereof as long as such embodiments
`and variations come within the scope of the appended claims
`and their equivalents.
`I claim:
`
`1. A wireless digital audio system comprising:
`at least one audio source to produce an audio output;
`at least one digital portable audio transmitter operatively
`coupled to said at least one audio source, said at least one
`portable audio transmitter comprising:
`a first analog low pass filter receiving audio output from
`said at least one audio source;
`a digital low pass filter;
`(ADC) operatively
`converter
`an analog-to-digital
`coupled between said first analog and digital low pass
`filters;
`a first encoder receiving output from said digital low
`pass filter and being configured to reduce intersymbol
`interference (ISI);
`a second channel encoder operatively coupled to said
`first encoder and adapted to reduce transmission
`errors;
`a digital modulator operatively coupled to said second
`channel encoder; and
`a differential phase shift key (DPSK) module receiving
`output from said digital modulator and a Lmique user
`code bit sequence and being configured for direct
`sequence spread spectrum (DSSS) communication,
`said DPSK module transmitting a corresponding
`DSSS signal having said audio output and the unique
`user code bit sequence;
`at least one portable audio receiver configured for digital
`wireless communication with said at least one por-
`
`SONY Exhibit 1006 - 0007
`
`SONY Exhibit 1006 - 0007
`
`

`

`US 7,412,294 B1
`
`5
`table audio transmitter and utilizing an embedded
`fuzzy logic detector wherein the fuzzy logic detector
`activates fuzzy logic rules and performs a defuzzifi-
`cation operation in response to a received user code to
`optimize digital signal processing, said at least one
`portable audio receiver comprising:
`a band pass filter (BPF) configured to process said trans-
`mitted DSSS signal;
`a direct conversion module receiving output from said
`BPF and being configured to capture the correct
`unique user code bit sequence embedded in said pro-
`cessed DSSS signal;
`a digital demodulator adapted to process output from
`said direct conversion module;
`a Viterbi decoder operatively coupled to said digital
`demodulator and generating a corresponding digital
`output;
`a source decoder processing said digital output from said
`Viterbi decoder and being configured to decode the
`digital signal encoded by said first encoder;
`a second analog low pass filter; and
`a digital -to-analog converter (DAC) operatively coupled
`between said source decoder and said second analog
`low pass filter, said second analog low pass filter
`generating an audio output corresponding to the
`decoded and converted digital signal; and
`at least one module adapted to reproduce said generated
`audio output, if the unique user code bit sequence is
`recognized, said audio output having been wirelessly
`transmitted from said at least one audio source with-
`out interference from other users or wireless devices
`
`6
`a second channel encoder operatively coupled to said first
`encoder and adapted to reduce transmission errors;
`a digital modulator operatively coupled to said second
`channel encoder; and
`a differential phase shift key (DPSK) module receiving
`output from said digital modulator and a unique user
`code and being configured for direct sequence spread
`spectrum (DSSS) communication, said DPSK module
`transmitting a corresponding DSSS signal;
`at least one audio receiver configured for digital wireless
`communication with said at least one portable digital
`audio transmitter and utilizing embedded fuzzy logic
`detector wherein the fuzzy logic detector activates fuzzy
`logic rules and performs a defuzzification operation in
`response to a received unique user code to enhance
`detection of the unique user code in said transmitted
`DSSS signal; said at least one audio receiver compris-
`ing:
`a band pass filter (BPF) configured to process said trans-
`mitted DSSS signal;
`a direct conversion module receiving output from said BPF
`and being configured to capture the correct bit sequence
`embedded in the received DSSS signal;
`a digital demodulator adapted to process output from said
`direct conversion module;
`a Viterbi decoder operatively coupled to said digital
`demodulator and generating a corresponding digital out-
`Put;
`a source decoder processing said digital output from said
`Viterbi decoder and being configured to decode the digi-
`tal signal encoded by said first encoder;
`a second analog low pass filter; and
`a digital-to-analog converter (DAC) operatively coupled
`between said source decoder and said second analog low
`pass filter, said second analog low pass filter generating
`the audio output;
`at least one module adapted to reproduce said amplified
`audio output, ifthe unique user code is recognized, said
`audio output having been Wirelessly transmitted from
`said at least one audio source to a user privately without
`interference from other users or wireless devices when
`
`operated in a shared space containing multiple users of
`wireless devices utilizing code division multiple access
`(CDMA) communication.
`11. The wireless digital audio system of claim 10, wherein
`said at least one audio amplifying module includes at least
`one power amplifier, said at least one power amplifier being
`configured to provide a low distortion audio signal output.
`12. The wireless digital audio system of claim 11, wherein
`said at least one audio reproducing module includes at least
`one headphone speaker, said at least one headphone speaker
`receiving said low distortion audio signal output from said at
`least one power amplifier.
`13. A wireless digital audio system, comprising:
`at least one audio source;
`at least one digital audio transmitter operatively coupled to
`said at least one audio source, said at least one audio
`transmitter comprising:
`a first analog low pass filter receiving audio output repre-
`sentative of music from said at least one audio source;
`a digital low pass filter;
`an analog-to-digital converter (ADC) operatively coupled
`between said first analog and digital low pass filters;
`a first encoder receiving output from said digital low pass
`filter and being configured to reduce intersymbol inter-
`ference (ISI);
`
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`SONY Exhibit 1006 - 0008
`
`when operated within a shared space containing mul-
`tiple users of wireless devices utilizing code divisio
`mult'ple access (CDMA) commu ication.
`2. "he wi‘e ess digital audio sys em 0 c aim 1, whe‘e'
`said BPF is a V 'ideband BPF.
`
`3. "he wi‘e ess digital audio sys em 0 c aim 1, whe‘e'
`said modula or is a 64-Ary modulator.
`4. "he wi‘e ess digital audio sys em 0 c aim 1, whe‘e'
`said demodLlator is a 64-Ary demodulator.
`5. "he wi‘e ess digital audio sys em 0 c aim 1, whe‘e'
`said generated audio output is in the approxi ate range of 20
`Hz to 20 kHz.
`
`6. "he wi‘e ess digital audio sys em 0 c aim 1, whe‘e'
`
`said soread spectrum signal is transmittec at about 2.4 GHz
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`via an omni-directional antenna.
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`7. "he wi‘e ess digital audio sys em 0 c aim 6, whe‘e'
`said spread spectrum signal is transmitted at a power ofabott
`100 milliwatts or less.
`
`8. "he wire ess digital audio sys em 0 c aim 1, wherein
`said ADC is a 4-bit analog-to-digital converter.
`9. "he wire ess digital audio sys em 0 c aim 1, wherein
`said BPF is operatively coupled to at leas o e antenna con-
`figured to receive said transmitted DSSS sig al.
`10. A wireless digital audio system; comprising:
`at least one audio source;
`at least one portable digital audio transm'tter operatively
`coupled to said at least one audio source, said at least one
`portable digital audio transmitter comprising:
`a first analog low pass filter receiving audio output from
`said at least one audio source;
`a digital low pass filter;
`an analog-to-digital converter (ADC) operatively coupled
`between said first analog and digital low pass filters;
`a first encoder receiving output from said digital low pass
`filter and being configured to reduce intersymbol inter-
`ference (lSl);
`
`SONY Exhibit 1006 - 0008
`
`

`

`US 7,412,294 B1
`
`8
`spectrum (DSSS) communication, said DPSK module
`transmitting a corresponding DSSS signal;
`at least one audio receiver configured for digital wireless
`communication with said at least one audio transmitter,
`said at least one audio receiver comprising:
`an embedded fuzzy logic detector wherein the fuzzy logic
`detector activates fuzzy logic rules and performs a
`defuzzification operation in response to a received
`unique user code to enhance detection ofthe unique user
`code;
`a band pass filter (BPF) configured to process said trans-
`mitted DSSS signal;
`a direct conversion module receiving output from said BPF
`and being configured to capture the correct unique user
`code bit sequence embedded in the received DSSS sig-
`nal;
`a digital demodulator adapted to process output from said
`direct conversion module;
`a Viterbi decoder operatively coupled to said digital
`demodulator and generating a corresponding digital out-
`Put;
`a source decoder processing said digital output from said
`Viterbi decoder and being configured to decode the digi-
`tal signal encoded by said first encoder;
`a second analog low pass filter; and
`a digital-to-analog converter (DAC) operatively coupled
`between said source decoder and said second analog low
`pass filter, said second analog low pass filter generating
`an audio output corresponding to the decoded and con-
`verted digital signal;
`at least one module adapted to amplify said generated
`audio 0 tput; and
`at least one module adapted to reproduce said amplified
`audio 0 tput, ifthe unique user code is recognized, said
`audio output having been Wirelessly transmitted from
`said at least one audio source to a user without interfer-
`
`ence fro otherusers or wireless devices when operated
`in a shared space containing multiple users of wireless
`transmission devices.
`
`
`
`15. The wi ‘eless digital audio system 0 claim 13, wherein
`said at least one audio source provides a
`alog output in the
`approx'mate ‘ange of 20 Hz to 20 kHz.
`16. The wi ‘eless digital audio system 0
`said at least one audio source provides a
`approx'mate ‘ange of 20 Hz to 20 kHz.
`17. The wi ‘eless digital audio system 0 claim 13, wherein
`said at
`east one audio source is a portable music player.
`18. The wi ‘eless digital audio system 0 claim 14, wherein
`said at
`east one audio source is a portable music player.
`19. A wire ess digital audio system, comprising: an audio
`$0111”C6
`0 provide an audio signal represe tative of music;
`a portable digital audio transmitter operatively coupled to
`sa'd audio source, said portable aud'o transmitter com-
`pr'sing:
`a first analog low pass filter receiving audio output from
`sa'd audio source; a digital low pass filter;
`an analog-to-digital converter (ADC) operatively coupled
`between said first analog and digital low pass filters;
`a first encoder receiving output from said digital low pass
`filter and being configured to reduce intersymbol inter-
`ference (ISI);
`a second channel encoder operatively coupled to said first
`encoder and adapted to reduced transmission errors;
`a digital modulator operatively coupled to said second
`channel encoder; and
`a differential phase shift key (DPSK) module receiving
`output from said digital modulator and being configured
`
`7
`a second channel encoder operatively coupled to said first
`encoder and adapted to reduce transmission errors;
`a digital modulator operatively coupled to said second
`channel encoder; and
`a differential phase shift key (DPSK) module receiving
`output from said digital modulator and a unique user
`code bit sequence and being configured for direct
`sequence spread spectrum (DSSS) communication, said
`DPSK module transmitting a corresponding DSSS sig-
`nal;
`at least one audio receiver configured for digital wireless
`communication with said at least one audio transmitter,
`said at least one audio receiver comprising:
`an embedded fuzzy logic detector wherein the fuzzy logic
`detector activates fuzzy logic rules and performs a
`defuzzification operation in response to a received
`unique user code to enhance detection ofthe unique user
`code;
`a band pass filter (BPF) configured to process said trans-
`mitted DSSS signal;
`a direct conversion module receiving output from said BPF
`and being configured to capture the correct unique user
`code bit sequence embedded in the received DSSS sig-
`nal;
`a digital demodulator adapted to process output from said
`direct conversion modulc;
`a Viterbi decoder operatively coupled to said digital
`demodulator and generating a corresponding digital out-
`put;
`a source decoder processing said digital output from said
`Viterbi decoder andbeing configured to decode the digi-
`tal signal encoded by said first encoder;
`a second analog low pass filter; and
`a digital-to-analog converter (DAC) operatively coupled
`between said source decoder and said second analog low
`pass filter, said second analog low pass filter generating
`an audio output corresponding to the decoded and con-
`verted digital signal; and
`at least one module adapted to reproduce said generated
`audio output, if the unique user code bit sequence is
`recognized, said audio output having been wirelessly
`transmitted from said at least one audio source to a user
`
`privately without interference from other users or wire-
`less devices when operated in a shared space containing
`multiple users of wireless transmission devices.
`14. A wireless digital audio system, comprising:
`at least one audio source;
`at least one digital audio transmitter operatively coupled to
`said at least one audio source, said at least one audio
`transmitter comprising:
`a first analog low pass filter receiving audio output from
`said at least one audio source;
`a digital low pass filter;
`(ADC) operatively
`converter
`an analog—to—digital
`coupled between said first analog and digital low pass
`filters;
`a first encoder receiving output from said digital low pass
`filter and being configured to reduce intersymbol inter-
`ference (181);
`a second channel encoder operatively coupled to said first
`encoder and adapted to reduce transmission errors;
`a digital modulator operatively coupled to said second
`channel encoder; and
`a differential phase shift key (DPSK) module receiving
`output from said digital modulator and a unique user
`code and being configured for direct sequence spread
`
`10
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`15
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`20
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`25
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`35
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`45
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`50
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`55
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`60
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`65
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`claim 14, wherein
`alog output in the
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`
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`SONY Exhibit 1006 - 0009
`
`SONY Exhibit 1006 - 0009
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`

`

`US 7,412,294 B1
`
`9
`for code division multiple access (CDMA) communica-
`tion, said DPSK module transmitting a corresponding
`CDMA signal with a unique user code;
`an audio receiver configured for digital wireless commu-
`nication with said portable digital audio transmitter and
`utilizing an embedded fuzzy logic detector wherein the
`fuzzy logic detector activates fuzzy logic rules and per-
`forms a defuzzification operation in response to a
`received unique user code to enhance detection of the
`unique user code, said audio receiver comprising:
`a band pass filter (BPF) configured to process said trans—
`mitted C