U.S. patent application number 15/003242 was filed with the patent office on 2018-09-20 for wireless digital audio music system.
The applicant listed for this patent is C. Earl Woolfork. Invention is credited to C. Earl Woolfork.
Application Number | 20180270561 15/003242 |
Document ID | / |
Family ID | 59360846 |
Filed Date | 2018-09-20 |
United States Patent
Application |
20180270561 |
Kind Code |
A9 |
Woolfork; C. Earl |
September 20, 2018 |
Wireless Digital Audio Music System
Abstract
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 headphone set. The audio
receiver is configured for digital wireless communication with the
audio transmitter. The digital audio receiver utilizes fuzzy logic
to optimize digital signal processing. Each of the digital audio
transmitter and receiver is configured for code division multiple
access (CDMA) communication. The wireless digital audio system
allows private audio enjoyment without interference from other
users of independent wireless digital transmitters and receivers
sharing the same space.
Inventors: |
Woolfork; C. Earl;
(Pasadena, CA) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Woolfork; C. Earl |
Pasadena |
CA |
US |
|
|
Prior
Publication: |
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Document Identifier |
Publication Date |
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US 20170214995 A1 |
July 27, 2017 |
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Family ID: |
59360846 |
Appl. No.: |
15/003242 |
Filed: |
January 21, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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13775754 |
Feb 25, 2013 |
9282396 |
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15003242 |
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13356949 |
Jan 24, 2012 |
9107000 |
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13775754 |
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12940747 |
Nov 5, 2010 |
8131391 |
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13356949 |
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12570343 |
Sep 30, 2009 |
7865258 |
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12940747 |
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12144729 |
Jul 12, 2008 |
7684885 |
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12570343 |
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10648012 |
Aug 26, 2003 |
7412294 |
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12144729 |
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10027391 |
Dec 21, 2001 |
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10648012 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G10L 19/167 20130101;
G10L 19/005 20130101; H04L 25/03006 20130101; G10L 25/33 20130101;
H04R 2420/07 20130101; H04B 1/707 20130101; H04R 5/00 20130101;
H04R 3/04 20130101; H04R 1/1041 20130101 |
International
Class: |
H04R 1/10 20060101
H04R001/10; G10L 19/005 20060101 G10L019/005; G10L 19/16 20060101
G10L019/16; G10L 25/33 20060101 G10L025/33; H04R 3/04 20060101
H04R003/04; H04B 1/707 20060101 H04B001/707 |
Claims
1. A wireless digital audio spread spectrum receiver, capable of
mobile operation, configured to receive a unique user code and an
audio signal representation from a digital audio spread spectrum
transmitter, said audio signal representation representative of
audio from a portable audio source, said digital audio spread
spectrum receiver operative to communicate wirelessly with said
digital audio spread spectrum transmitter, said digital audio
spread spectrum receiver comprising: a direct conversion module
configured to receive wireless spread spectrum signal transmissions
representative of the unique user code and the audio signal
representation, wherein the received transmissions are encoded to
reduce intersymbol interference; a digital demodulator configured
to demodulate a received transmission and to generate a demodulated
transmission, the digital demodulator configured to perform first
demodulation and second demodulation, wherein said second
demodulation is differential phase shift keying (DPSK)
demodulation; a decoder operative to decode the demodulated
transmission and to generate a receiver audio signal
representation, the decoder configured to decode reduced
intersymbol interference coding and to decode representations of
audio in the frequency range of 20 Hz to 20 kHz, said decoding
being separate from said first and second demodulation; a
digital-to-analog converter (DAC) configured to generate an audio
output from said receiver audio signal representation; and a
speaker configured to reproduce said generated audio output,
wherein said reproduction does not include audible audio content
originating from any transmitted audio signals in the wireless
digital audio spread spectrum transmitter spectrum that do not
originate from said digital audio spread spectrum transmitter;
wherein the wireless digital audio spread spectrum receiver is
configured to use independent code division multiple access
communication and to use the received unique user code to
communicate only with said wireless digital audio spread spectrum
transmitter for the duration of a wireless connection.
2. The wireless digital audio spread spectrum receiver of claim 1,
wherein said audio from said portable audio source is music.
3. A portable spread spectrum audio receiver, configured to receive
and store a unique user code, said portable spread spectrum
receiver configured to receive wireless transmissions from a spread
spectrum transmitter, said wireless transmissions representative of
an audio signal representation, said portable spread spectrum audio
receiver comprising: a direct conversion module configured to
receive wireless transmissions representative of the audio signal
representation, wherein the received wireless transmissions are
encoded to reduce intersymbol interference; a digital demodulator
configured to demodulate a received transmission and to generate a
demodulated transmission, the digital demodulator configured to
perform first demodulation and second demodulation, wherein said
second demodulation is differential phase shift keying (DPSK)
demodulation; a decoder operative to decode the demodulated
transmission and to generate a receiver audio signal
representation, the decoder configured to decode reduced
intersymbol interference coding and to decode representations of
audio in the frequency range of 20 Hz to 20 kHz, said decoding
being separate from said first and second demodulation; a
digital-to-analog converter (DAC) configured to generate an audio
output from said receiver audio signal representation; and a
speaker configured to reproduce said generated audio output,
wherein said reproduction does not include audible audio content
originating from any transmitted audio signals in the spread
spectrum transmitter spectrum that do not originate from said
spread spectrum transmitter; wherein the portable spread spectrum
audio receiver is configured to use independent code division
multiple access communication and to use the received unique user
code to communicate only with said spread spectrum transmitter for
the duration of a wireless connection.
4. The portable spread spectrum receiver of claim 3, wherein the
audio signal representation represents music.
5. A wireless digital coded audio spread spectrum transmitter
operatively coupled to a portable audio player and configured to
transmit a unique user code and a representation of an audio
signal, wherein said digital coded audio spread spectrum
transmitter is configured to wirelessly communicate with a digital
audio spread spectrum receiver and is configured to be moved in any
direction during operation, said wireless digital coded audio
spread spectrum transmitter comprising: an encoder operative to
encode a first representation of an audio signal to reduce
intersymbol interference associated with a transmitted
representation of the audio signal, said encoder configured to
process signals in the frequency range of 20 Hz to 20 kHz for
representation in said first representation of an audio signal; a
digital modulator configured to modulate the first representation
of the audio signal, said digital modulator configured to perform a
first modulation and a second modulation, said digital modulator
configured to generate a second representation of the audio signal,
wherein said second modulation is differential phase shift keying
(DPSK) modulation, and wherein said first modulation and said
second modulation are separate from encoding and processing by the
encoder; and wherein the wireless digital coded audio spread
spectrum transmitter is configured to use the second representation
of the audio signal and to use independent code division multiple
access communication to wirelessly transmit a transmitted
representation of the audio signal, and wherein the transmitted
unique user code distinguishes the transmitted representation of
the audio signal from other transmitted audio signals in the spread
spectrum transmitter spectrum, said other transmitted audio signals
not originating from said wireless digital coded audio spread
spectrum transmitter.
6. The wireless digital coded audio spread spectrum transmitter of
claim 5, wherein the first representation of an audio signal is
representative of music.
7. The wireless digital audio spread spectrum receiver of claim 1,
wherein said first demodulation is 64-ary demodulation.
8. The portable spread spectrum receiver of claim 3, wherein said
first demodulation is 64-ary demodulation.
9. The wireless digital coded audio spread spectrum transmitter of
claim 5, wherein the first modulation is 64-ary modulation.
Description
[0001] This continuation application claims the benefit of U.S.
patent application Ser. No. 13/775,754 filed Feb. 25, 2013, which
is a continuation application claiming benefit of U.S. patent
application Ser. No. 13/356,949 filed Jan. 24, 2012, which was a
continuation application claiming the benefit of U.S. patent
application Ser. No. 12/940,747 filed Nov. 5, 2010, now U.S. Pat.
No. 8,131,391, which was a continuation application claiming the
benefit of U.S. patent application Ser. No. 12/570,343 filed Sep.
30, 2009, now U.S. Pat. No. 7,865,258, which was a continuation
claiming the benefit of U.S. patent application Ser. No. 12/144,729
filed Jul. 12, 2008, now U.S. Pat. No. 7,684,885, which was a
continuation claiming benefit of U.S. patent application Ser. No.
10/648,012 filed Aug. 26, 2003, now U.S. Pat. No. 7,412,294, which
was a continuation-in-part claiming benefit from U.S. patent
application Ser. No. 10/027,391, filed Dec. 21, 2001, for "Wireless
Digital Audio System," published under US 2003/0118196 A1 on Jun.
26, 2003, now abandoned, the disclosures of which are incorporated
herein in their entireties by reference.
BACKGROUND OF THE INVENTION
[0002] This invention relates to audio player devices and more
particularly to systems that include headphone listening devices.
The new audio system uses an existing headphone 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 wireless transmission of a signal to a set
of battery powered receiving headphones.
[0003] Use of audio headphones with audio player devices such as
portable CD players, portable cassette players, portable A.M./F.M.
radios, laptop/desktop computers, 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
connected by wire.
[0004] There are also known wireless headphones that may receive
A.M. and F.M. radio transmissions. However, they do not allow use
of a simple plug in (i.e., plug in to the existing analog audio
headphone jack) battery powered transmitter for connection to any
music audio player device jack, such as the above mentioned music
audio player devices, for coded wireless transmission and reception
by headphones of audio music for private listening without
interference where multiple 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.
[0005] There is a need for a battery powered simple connection
system for existing music audio player devices (i.e., the
previously mentioned music devices), to allow coded digital
wireless transmission (using a battery powered transmitter) to a
headphone receiver (using a battery powered receiver headphones)
that accomplishes private listening to multiple users occupying the
same space without the use of wires.
SUMMARY OF THE INVENTION
[0006] 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 bit detection.
A battery-powered digital transmitter may include a headphone plug
in communication with any suitable music audio source. For
reception, 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 of the 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
conventional cable connections.
[0007] These and other features, aspects and advantages of the
present invention will become better understood with reference to
the following drawings, description and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Some aspects of the present invention are generally shown by
way of reference to the accompanying drawings in which:
[0009] FIG. 1 schematically illustrates a wireless digital audio
system in accordance with the present invention;
[0010] FIG. 2 is a block diagram of an audio transmitter portion of
the wireless digital audio system of FIG. 1.;
[0011] FIG. 3 is a block diagram of an audio receiver portion of
the wireless digital audio system of FIG. 1; and
[0012] 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
[0013] 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.
[0014] 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
connected 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 spectrum 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 conversion, 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 (differential
phase shift key) transmitter or module 48, is utilized. The battery
powered transmitter 20 may contain a code generator 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) spectrum utilized (as taken from the Industrial,
Scientific and Medical (ISM) band) may be approximately 2.4 GHz.
The power radiated by the transmitter adheres to the ISM
standard.
[0015] 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 spread spectrum modulated
signal from transmit antenna 24 may 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 transmitted unique code, in the battery powered
receiver 50 headphones. 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 may utilize
embedded fuzzy logic 61 (as graphically 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 particular user.
Other code words from wireless digital audio systems 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 enjoyment. The resulting summed digital signal
from receiving summary element 58 and direct conversion receiver or
module 56 may be processed by a 64-Ary demodulator 62 to demodulate
the signal elements modulated in the audio transmitter 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 transmitter 20. A source decoder 68 may further
decode the coding applied by encoder 36.
[0016] Each receiver headphone 50 user may be able to listen
(privately) to high fidelity audio music, using any of the audio
devices listed previously, without the use of wires, and without
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.
[0017] 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 stream rate
less than or equal to 1.0 Mbps.
[0018] The user code bits in each packet may be received and
detected by a fuzzy logic detection sub-system 61 (as an option)
embedded in the headphone receiver 50 to optimize audio receiver
performance. For each consecutive packet received, the fuzzy logic
detection sub-system 61 may compute a conditional 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 (1)/low (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.
[0019] 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 a 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.
[0020] 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
transmitted packet. Fuzzy logic detection sub-system 61 may be used
in battery-powered headphone receiver 50 to enhance overall system
performance.
[0021] The next step may process the digital signal to return the
signal to analog or base band format for use in powering speaker(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 for audible enjoyment by a user wearing
headphones 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 utilized in
accordance with the teachings herein. Accordingly, the drawings and
description are illustrative and not meant to be a limitation
thereof.
[0022] 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 referenced. Thus, it is
intended that the invention cover all embodiments and variations
thereof as long as such embodiments and variations come within the
scope of the appended claims and their equivalents.
* * * * *