US007412294B1
`
`US 7,412,294 B1
`(10) Patent No:
`a2) United States Patent
`Woolfork
`(45) Date of Patent:
`Aug. 12, 2008
`
`
`(54) WIRELESS DIGITAL AUDIO SYSTEM
`
`3/2003 Mooneyetal. .......... 455/41
`2003/0045235 AL*
`2004/0223622 Al* 11/2004 Lindemannetal. ........... 381/79
`
`(76)
`
`Inventor: C. Earl Woolfork, 500 Santa Paula Ave.,
`Pasadena, CA (US) 91107
`
`(*) Notice:
`
`Subject to any disclaimer, the term ofthis
`patent is extended or adjusted under 35
`US.C. 154(b) by 199 days.
`
`(22)
`
`(21) Appl. No.: 10/648,012
`,
`Jed:
`Aug. 26, 2003
`Filed:
`on
`Related U.S, Application Data
`(63) Continuation-in-part of application No. 10/027,391,
`filed on Dec. 21, 2001, now abandoned.
`;
`
`o
`
`OTHER PUBLICATIONS
`Specification of the Bluetooth System, Version 1.0 B, pp. 17-27,
`4144, 81-86, 143-147."
`Pohlman,K. C. Principles of Digital Audio. McGraw-Hill, Inc., 3°@
`ed. 1995. pp. 155-157.*
`SAA7360 Bitstream conversion ADC for digital audio systems.
`Datasheet[online]. Philips Semiconductors, 1995 [retrieved on Dec.
`15, 2005]. Retrieved from the Internet: <URL: http:/Awww.ortodox-
`ism.ro/datasheets/philips/SAA7360GPpdf>.*
`wikipeda.comentryfor Viterbi Decoder.*
`wikipedia.com entryfor Viterbi Algorithm.*
`A Tutorial on Convolutional Coding with Viterbi Decoding; Chip
`Flemming.”
`www.telecomspace.com overview for CDMA.*
`“Digital Communication Techniques” by Simon, Hinedi and
`Lindsey.
`
`(Continued)
`
`(51)
`
`g
`
`(56)
`
`Int.Cl.
`(2006.01)
`GO6F 17/00
`(2008.01)
`HO4H 40/00
`Primary Examiner—Suhan Ni
`(52) US. CM.
`cacccccsssccsssecscssseensesenseee 700/94; 455/3.06
`Assistant Examiner—Andrew C Flanders
`(58) Field of Classification Search ......c.c. 700/94,
`(74) Attorney, Agent, or I’irm—Megan LE. Lyman
`714/709,780, 795, 794, 75; 706/8, 9: 455/3.06,
`455/41, 66.1, 41.3, 564.1, 412, 413; 375/224,
`©?)
`ABSTRACT
`375/295-297, 346, 348, 219, 341, 140,147,
`A wireless digital audio system includes a portable audio
`375/146, 130, 340, 316, ee%
`source with a digital audio transmitter operatively coupled
`lication
`file
`f
`let
`hi t
`~
`thereto and an audio receiver operatively coupled to a head-
`Ce APplnCalon
`Te
`TOF COMIPNCE Search,
`DISLOLY.
`phone set. The audio receiveris configured for digital wire-
`References Cited
`less communication with the audio transmitter. The digital
`_
`audio receiver utilizes fuzzy logic to optimize digital signal
`US. PATENT DOCUMENTS
`processing. Each ofthe digital audio transmitter and receiver
`5.491.839 A *
`2/1996 Schotz .....
`_.. 485/39
`
`is configured for code divisionmultiple access (CDMA) com-
`5771441 A *
`6/1998 Altstatt .....
`., 455/66.1
`
`
`5,790,595 A * ... 375/224~~‘Munication. The wireless digital audio system allowsprivate8/1998 Benthin et al.
`5,946,343 A *
`8/1999 Schotzetal. ccs 375/141
`audio enjoyment without interference from other users of
`6,342,844 BL*
`1/2002 Rozin ceccccssssscccsssssseeees 340/933
`independent wireless digital transmitters and receivers shar-
`.. 725/129
`6,418,558 BL*
`7/2002 Roberts et al.
`ing the samespace.
`
`1/2004 Lavelleetal. ow... 725/75
`6,678,892 BL*
`6,982,132 BL*
`1/2006 Goldneretal.
`.......0.... 429/162
`
`
`
`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”byStein 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 of 3
`
`US 7,412,294 B1
`
`
`
`FIG.1
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`SONY Exhibit 1006 - 0003
`
`SONY Exhibit 1006 - 0003
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`SONY Exhibit 1006 - 0004
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`U.S.Patent
`
`
`Aug.12,2008
`Sheet3of3
`
`US7,412,294B1
`
`SONY Exhibit 1006 - 0005
`
`
`

`

`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 abandonedfor “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.
`
`BACKGROUNDOF THE INVENTION
`
`10
`
`This invention relates to music audio player devices and
`moreparticularly to systemsthat include headphonelistening
`devices. The new audio music system uses an existing head-
`phonejack (i.e., this is the standard analog headphonejack
`that connects to wired headphones) of a music audio player
`(1.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 ofa signalto 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 andthelike, have been in use for many
`years. These systems incorporate an audio source having an
`analog headphone jack to which headphones maybe con-
`nected by wire.
`There are also known wireless headphones that may
`receive A.M.and F.M.radio transmissions. However, they do
`notallow use ofa simple plug in(..e., plug in to the existing
`analog audio headphonejack) battery powered transmitter for
`connection to any music audioplayer 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 sourceandthe
`headphonesto 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 headphonereceiver (using battery powered receiver head-
`phones) that accomplishesprivate listening to multiple users
`occupying the same space without the use of wires.
`SUMMARYOF THE INVENTION
`
`The present invention is generally directed to a wireless
`digital audio system for coded digital transmission of an
`audio signal from any audioplayer with an analog headphone
`jack to a receiver headphone located away from the audio
`player. Fuzzy logic technology maybeutilized by the system
`to enhance bit detection. A battery-powereddigital transmit-
`ter may include a headphoneplug in communication with any
`suitable music audio source. Forreception, a battery-powered
`headphone receiver may use embedded fuzzy logic to
`enhanceuser code bit detection. Fuzzylogic 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 connections.
`These and other features, aspects and advantages of the
`present invention will become better understood with refer-
`ence to the following drawings, description andclaims.
`
`Someaspects of the present invention are generally shown
`by wayofreference to the accompanying drawings in which:
`FIG. 1 schematically illustrates a wireless digital audio
`system in accordance with the present invention;
`FIG.21s a block diagram ofan audio transmitter portion of
`the wireless digital audio system of FIG.1;
`FIG.3 is a block diagram of an audio receiver portion 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
`embodimentof 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 ofillustrating the generalprinciples of
`the invention.
`
`20
`
`Referring to FIGS. 1 through 3, a wireless digital audio
`music system 10 mayinclude a battery powered transmitter
`20 connectedto a portable music audio player or music audio
`source 80. The battery powered wireless digital audio music
`transmitter 20 utilizes an analogto digital converter or ADC
`32 and may be connected to the music audio source 80 analog
`headphone jack 82 using a headphone plug 22. The battery
`powered transmitter 20 mayhave a transmitting antenna 24
`that may be omni-directional for transmitting a spread spec-
`trum modulated signal to a receiving antenna 52ofa 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, fuzzylogic 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 maybe processed bya digital low
`passfilter. To reducethe 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 48is utilized.
`Thebattery powered transmitter 20 may contain a code gen-
`erator 44 that maybe used to create a unique user code. The
`unique user code generatedis specifically associated with one
`wireless digital audio system user, and it is the only code
`recognized by the battery powered headphone receiver 50
`operated bya particular user. The radio frequency (RF) spec-
`trum utilized (as taken from the Industrial, Scientific and
`Medical (ISM) band) may be approximately 2.4 GHz. The
`powerradiated bythe transmitter adheresto the ISM stan-
`dard.
`
`Particularly, the received spread spectrum signal may be
`communicated to a 2.4 GHz direct conversionreceiver or
`
`module 56. Referring to FIGS. 1 through 4,the spread spec-
`trum modulated signal from transmit antenna 24
`may be
`received by receiving antenna 52 and then processed by
`spread spectrumdirect conversion receiver or module 56 with
`a receiver code generator 60 that contains the sametransmit-
`ted unique code, in the battery powered receiver 50 head-
`phones. The transmitted signal from antenna 24
`may be
`received by receiving antenna 52 and communicated to a
`wideband bandpass filter
`(BPF). The battery powered
`receiver 50 mayutilize 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 ofa signal code wordthat
`was transmitted. by audio transmitter 20 specific to a particu-
`lar user. Other code words from wireless digital audio sys-
`tems 10 mayappear 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)
`maybe usedto provide eachuser independent audible enjoy-
`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 modulatedin the audiotrans-
`mitter 20. A block de-interleaver 64 may then decodethe 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 encoder38 in audio transmit-
`ter 20. A source decoder 68 may further decode the coding
`applied by encoder 36.
`Each receiver headphone 50 user maybe able to listen
`(privately) to highfidelity audio music, using anyofthe audio
`deviceslisted previously, without the use of wires, and with-
`out interference from anyother receiver headphone 50user,
`even when operated within a shared space. The fuzzylogic
`detection technique 61 used in the receiver 50 could provide
`greater user separation through optimizing code division in
`the headphonereceiver.
`The battery powered transmitter 20 sends the audio music
`information to the battery powered receiver 50 in digital
`packet format. These packets may flow to create a digital bit
`streamrate of less than or equal to 1.0 Mbps.
`Theuser code bits in each packet mayalso be received and
`detected by a fuzzy logic detection sub-system 61 (as an
`option) embedded in headphonereceiver 50 to optimize audio
`receiver performance. For each consecutive packet received,
`fuzzylogic detection sub-system 61 may compute a condi-
`tional density with respect to the context and fuzzinessofthe
`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) eventin 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 producesa lowprobability ofbit 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 inputsto validation
`outputs. These rules maybe developed asif-then statements.
`Fuzzy logic detection sub-system 61 in battery-powered
`headphonereceiver 50 utilizes the if-then fuzzyset to map the
`received user code bits into two values: a low (0 or -1) anda
`high (1). Thus,as the user codebits are received, the “if” rules
`map the signal bit energy to the fuzzy set low value to some
`degree andto the fuzzyset 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 energyrepresentation. Dueto additive noise, the user
`code bit energy may have some membership to lowand high
`as represented in FIG. 4. Theif-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,1.e., a
`measure of the membership degree to which a set may be a
`subset of anotherset, may be to one.
`
`
`
`35
`
`40
`
`4
`The if-thenrule parts that make upthe fuzzylogic detection
`sub-system 61 must be followed by a defuzzifying operation.
`This operation reducesthe aforementioned fuzzyset to a bit
`energy representation (i.e., -1 or 1) that is received by the
`transmitted packet. Fuzzy logic detection sub-system 61 may
`be usedin battery-powered headphonereceiver 50 to enhance
`overall system performance.
`The next step mayprocess the digital signal to return the
`signal to analog or base band format 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 audiosignal.
`An analog low pass filter 72 maybeusedtofilter the analog
`audio music signal to pass a signal in the approximate 20 Hz
`to 20 kHz frequency range andfilter other frequencies. The
`analog audio music signal may then be processed bya 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
`someof the embodiments described hereinabove are merely
`illustrative of the general principles of the present invention.
`Other modificationsor variations may be employed that are
`within the scope of the invention. Thus, by wayof example,
`but not of limitation, alternative configurations may be uti-
`lized in accordance with the teachings herein. Accordingly,
`the drawings anddescription are illustrative and not meantto
`be a lumitation thereof.
`Moreover, all terms should be interpreted in the broadest
`possible mannerconsistent with the context.In particular, the
`terms “comprises”and “comprising” should be interpreted as
`referring to elements, components, or steps in anon-exclusive
`manner, indicatingthatthe 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 coverall embodi-
`ments and variations thereof as long as such embodiments
`and variations come within the scope ofthe 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
`coupledto 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 passfilter;
`(ADC) operatively
`converter
`an analog-to-digital
`coupled betweensaidfirst analog anddigital low pass
`filters;
`a first encoder receiving output from said digital low
`passfilter and being configuredto 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 uniqueuser
`code bit sequence and being configured for direct
`sequence spread spectrum (DSSS) communication,
`said DPSK module transmitting a corresponding
`DSSSsignal having said audio output and the unique
`user code bit sequence;
`at least one portable audio receiver configuredfor digital
`wireless communication with said at least one por-
`
`SONY Exhibit 1006 - 0007
`
`SONY Exhibit 1006 - 0007
`
`

`

`when operated within a shared space containing mul-
`tiple users of wireless devices utilizing code divisio
`$
`multiple access (CDMA) communication.
`2. The wireless digital audio system of claim 1, wherei
`said BPF is a wideband BPF.
`
`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 responseto a received user code to
`optimize digital signal processing, said at least one
`portable audio receiver comprising:
`a bandpassfilter (BPF) configured to processsaid trans-
`mitted DSSSsignal;
`a direct conversion module receiving output from said
`BPF and being configured to capture the correct
`unique user code bit sequence embeddedin said pro-
`cessed DSSSsignal;
`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;
`asource decoderprocessing said digital output from said
`Viterbi decoder and being configured to decode the
`digital signal encodedbysaid first encoder;
`a second analog low passfilter, and
`a digital -to-analog converter (DAC)operatively coupled
`between said source decoder and said second analog
`low passfilter, said second analog lowpass 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 adaptedto reduce transmissionerrors;
`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 fuzzylogic detector activates fuzzy
`logic rules and performsa defuzzification operation in
`response to a received unique user code to enhance
`detection of the unique user code in said transmitted
`DSSSsignal, said at least one audio receiver compris-
`ing:
`a bandpassfilter (BPF) configured to process said trans-
`mitted DSSSsignal;
`a direct conversion module receiving output from said BPF
`and being configured to capture the correct bit sequence
`embeddedin 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 correspondingdigital out-
`put:
`a source decoder processing said digital output from said
`Viterbi decoder and being configured to decode the digi-
`tal signal encoded bysaidfirst encoder;
`a second analoglow passfilter; and
`a digital-to-analog converter (DAC) operatively coupled
`between said source decoder andsaid second analog low
`pass filter, said second analog low passfilter 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 userprivately without
`interference from otherusers 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 includesat 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 includesat least
`one headphonespeaker, 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 passfilter receiving audio output repre-
`sentative of music from said at least one audio source;
`a digital lowpass filter;
`an analog-to-digital converter (ADC)operatively coupled
`betweensaid first analog and digital low passfilters;
`a first encoder receiving output from said digital low pass
`filter and being configured to reduce intersymbol inter-
`ference (ISD;
`
`10
`
`20
`
`35
`
`40
`
`45
`
`50
`
`60
`
`65
`
`SONY Exhibit 1006 - 0008
`
`
`
`
`
`
`
`3. The wireless digital audio system of claim 1, wherei
`said modulator is a 64-Ary modulator.
`4. The wireless digital audio system of claim 1, wherei
`said demodulator is a 64-Ary demodulator.
`5. The wireless digital audio system of claim 1, wherei
`said generated audio outputis in the approximaterangeof 20
`Hzto 20 kHz.
`
`6. The wireless digital audio system of claim 1, wherei
`said spread spectrum signal is transmitted at about 2.4 GHz
`via an omni-directional antenna.
`$
`7. The wireless digital audio system of claim 6, wherei
`said spread spectrumsignalis transmitted at a powerofabout
`100 milliwatts orless.
`
`
`
`
`
`
`
`
`
`
`
`
`
`8. The wireless digital audio system of claim 1, wherein
`said ADCis a 4-bit analog-to-digital converter.
`9. The wireless digital audio system of claim 1, wherein
`said BPFis operatively coupled to at least one antenna con-
`figured to receive said transmitted DSSSsignal.
`10. A wireless digital audio system, comprising:
`at least one audio source;
`at least one portable digital audio transmitter operatively
`coupledto said at least one audio source,said at least one
`portable digital audio transmitter comprising:
`a first analog lowpassfilter receiving audio output from
`said at least one audio source;
`a digital lowpass filter;
`an analog-to-digital converter (ADC)operatively coupled
`betweensaidfirst analog and digital low passfilters;
`a first encoder receiving output from said digital low pass
`filter and being configured to reduce intersymbol inter-
`ference (ISI);
`
`SONY Exhibit 1006 - 0008
`
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`US 7,412,294 B1
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`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 fuzzylogic detector wherein the fuzzy logic
`detector activates fuzzy logic rules and performs a
`defuzzification operation in response to a received
`unique user code to enhancedetection ofthe unique user
`code;
`a bandpassfilter (BPF) configured to process said trans-
`mitted DSSSsignal;
`a direct conversion module receiving output from said BPF
`and being configuredto capture the correct unique user
`code bit sequence embeddedin 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 correspondingdigital out-
`put:
`a source decoder processing said digital output from said
`Viterbi decoder and being configured to decode the digi-
`tal signal encoded bysaidfirst encoder;
`a second analoglow passfilter; and
`a digital-to-analog converter (DAC) operatively coupled
`between said source decoder andsaid second analog low
`pass filter, said second analoglow passfilter generating
`an audio output correspondingto the decoded and con-
`verted digital signal:
`at least one module adapted to amplify said generated
`audio output; and
`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 without interfer-
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`a second channel encoder operatively coupledto said first
`encoder and adaptedto reduce transmissionerrors;
`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
`cade 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
`uniqueusercode to enhance detection ofthe unique user
`cade;
`a bandpassfilter (BPF) configured to process said trans-
`mitted DSSSsignal;
`a direct conversion modulereceiving 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 processingsaid digital output from said
`Viterbi decoder and being configured to decode the digi-
`tal signal encoded bysaidfirst encoder;
`a second analoglowpassfilter; and
`a digital-to-analog converter (DAC)operatively coupled
`between said source decoderandsaid second analog low
`pass filter, said second analoglowpassfilter 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
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`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 lowpassfilter receiving audio output from
`said at least one audio source;
`a digital low passfilter;
`(ADC) operatively
`converter
`an analog-to-digital
`coupled betweensaidfirst analog anddigital 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 coupledto said first
`encoder and adaptedto reduce transmissionerrors;
`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
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`claim 14, wherein
`alog output in the
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`otherusersor wireless devices when operated
`ence from
`in a shared space containing multiple users of wireless
`transmission devices.
`15. Thewireless digital audio system of claim 13, wherein
`said at least one audio source provides a
`alog output in the
`approximate range of 20 Hz to 20 kHz.
`16. The wireless digital audio system o
`said at least one audio source provides a
`approximate range of 20 Hz to 20 kHz.
`17. The wireless digital audio system of claim 13, wherein
`said at
`east one audio source is a portable musicplayer.
`18. Thewireless digital audio system of claim 14, wherein
`said at
`east one audio source is a portable musicplayer.
`19. A wireless digital audio system, comprising: an audio
`source
`© provide an audio signal representative of music;
`a portable digital audio transmitter operatively coupled to
`said audio source, said portable audio transmitter com-
`prising:
`a first analog low pass filler receiving audio output from
`said audio source; a digital low pass filter;
`an analog-to-digital converter (ADC)operatively coupled
`between said first analog and digital low passfilters;
`a first encoder receiving output from said digital low pass
`filter and being configured to reduce intersymbol inter-
`ference (ISD;
`a second channel encoder operatively coupled to said first
`encoder and adapted to reduced transmissionerrors;
`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
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`SONY Exhibit 1006 - 0009
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`SONY Exhibit 1006 - 0009
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`US 7,412,294 B1
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`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 ofthe
`unique user code, said audio receiver comprising:
`a bandpassfilter (BPF) configured to process said trans-
`mitted CDMA signal;
`a direct conversion module receiving output from said BPF
`and being configuredto capture the correct bit sequence
`embeddedin the received spread spectrum 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,
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`a source decoder processing said digital output from said
`Viterbi decoder and being configured to decode the