Derivative works — US Patent 9107000

In my capacity as a senior US patent analyst, I have reviewed the provided text for US Patent 9,107,000. The initial analysis indicating the patent was not found is superseded by this new information. The following analysis is based on the patent text sourced from Google Patents (https://patents.google.com/patent/[US9107000](/patent/US9107000)/en) and is performed as of today's date, May 13, 2026.

This patent describes a wireless digital audio system composed of a mobile, battery-powered transmitter that connects to an analog audio source, and a corresponding mobile, battery-powered headphone receiver. The core innovation lies in the use of Code Division Multiple Access (CDMA) with a unique user code for each transmitter-receiver pair, allowing multiple users to operate in the same physical space with minimal interference. The claims emphasize the use of specific coding techniques to reduce intersymbol interference (ISI) and the description discloses the optional use of fuzzy logic to enhance user code detection.

Defensive Disclosure and Prior Art Generation for US Patent 9,107,000

This document serves as a defensive disclosure to establish prior art for technologies and applications derived from the core concepts of US Patent 9,107,000. The following descriptions are intended to be enabling for a person skilled in the art.

I. Derivative Variations on Core Claims

The core claims of US 9,107,000 relate to a mobile wireless audio receiver (Claim 1) and a corresponding transmitter (Claim 8) that utilize CDMA and specialized coding to ensure interference-free operation. The following variations expand upon this foundation.

Axis 1: Material & Component Substitution

Derivative 1.1: Graphene-Diaphragm Receiver with Integrated GaN Front-End

Enabling Description: The headphone receiver, as described in Claim 1, is modified to use speaker drivers (75) constructed from graphene diaphragms. These drivers offer a superior frequency response (5 Hz to 50 kHz) and lower distortion due to graphene's high stiffness-to-mass ratio. The direct conversion module (56) is implemented using a Gallium Nitride (GaN) Low-Noise Amplifier (LNA) front-end. This GaN LNA provides a lower noise figure (< 0.5 dB) and higher linearity (IIP3 > +15 dBm) in the 2.4 GHz ISM band compared to traditional silicon-based components, significantly improving the receiver's sensitivity and its ability to reject strong, out-of-band interfering signals. The entire RF and baseband processing chain is packaged in a single System-in-Package (SiP) module for miniaturization.

Diagram:

graph TD
    subgraph Headphone Receiver (Claim 1 Derivative)
        A[Receiving Antenna] --> B{GaN LNA};
        B --> C[2.4 GHz Direct Conversion Module];
        D[Receiver Code Generator] --> E[Summing Element];
        C --> E;
        E --> F[Demodulator/Decoder];
        F --> G[DAC];
        G --> H[Power Amplifier];
        H --> I[Graphene Diaphragm Speakers];
    end

Derivative 1.2: Conductive Polymer Transmitter Housing with Integrated Antenna

Enabling Description: The transmitter, as described in Claim 8, is constructed with a housing made from a conductive polymer composite, such as polyaniline (PANI) blended with ABS plastic. This material allows the entire external housing of the transmitter to function as the transmitting antenna (24). This integrated, omnidirectional antenna design eliminates the need for a separate internal or external antenna component, reducing size and manufacturing complexity. The ground plane for the antenna is formed by the PCB's ground layer, and the antenna is fed by a single pin from the spread spectrum transmitter module (48). The polymer's conductivity is tuned during manufacturing to optimize impedance matching (50 ohms) for the 2.4 GHz ISM band.

Diagram:

graph TD
    subgraph Transmitter (Claim 8 Derivative)
        A[Audio Source] --> B[ADC];
        B --> C[Encoder & ISI-Reduction Coder];
        C --> D[Modulator];
        D --> E[Spread Spectrum Module];
        E --> F{Antenna Feed Point};
        F -- Integrated into Housing --> G[Conductive Polymer Housing/Antenna];
    end

Axis 2: Operational Parameter Expansion

Derivative 2.1: Cryogenic-Environment Auditory Monitoring System

Enabling Description: The system is adapted for operation in cryogenic environments (-100°C to -200°C), such as for communication between technicians handling liquefied natural gas or servicing superconducting equipment. The transmitter and receiver housings are made of a cryo-compatible polymer like PEEK. All electronic components, including the DSP, RF modules, and amplifiers, are certified for cryogenic operation. The batteries are replaced with specialized lithium thionyl chloride cells capable of functioning at low temperatures. The "reduced intersymbol interference coding" algorithm described in Claim 1 is specifically optimized to account for the altered signal propagation characteristics and increased thermal noise floor of the cryogenic environment.

Diagram:

stateDiagram-v2
    [*] --> Inactive
    Inactive --> Active: Power On
    Active --> Transmitting: Audio Detected
    Transmitting --> Standby: Audio Paused
    Standby --> Transmitting: Audio Resumes
    state Active {
        state "Environmental Compensation" as EC
        EC: Adjusts ISI coding coefficients based on temperature sensor input (< -100°C).
    }

Derivative 2.2: Underwater Diver Communication Network

Enabling Description: The audio system is re-engineered for underwater use by divers. The RF communication (2.4 GHz) is replaced with a short-range acoustic communication system operating in the 30-40 kHz ultrasonic band. The transmitter (worn by one diver) converts the user's speech from a full-face mask microphone into a digital signal, which is then encoded with the CDMA user code and ISI-reduction code as per Claim 8. This digital signal modulates the 35 kHz acoustic carrier wave, which is transmitted by a piezoelectric transducer. The receiver (worn by another diver) uses a hydrophone to capture the acoustic signal. The direct conversion module is replaced by an acoustic front-end and demodulator. The unique CDMA codes allow multiple pairs of divers to communicate in close proximity without crosstalk.

Diagram:

sequenceDiagram
    participant Diver_A_Transmitter
    participant Water_Medium
    participant Diver_B_Receiver
    Diver_A_Transmitter->>Water_Medium: Transmit CDMA-encoded acoustic packet (35 kHz)
    Water_Medium->>Diver_B_Receiver: Propagate acoustic signal
    Diver_B_Receiver->>Diver_B_Receiver: Decode packet using Diver A's unique code

Axis 3: Cross-Domain Application

Derivative 3.1: Aerospace - Interference-Free Avionics Data Bus

Enabling Description: The core CDMA communication protocol is adapted for a wireless data bus within an aircraft, replacing heavy copper wiring. Multiple sensors (e.g., temperature, pressure, strain gauges) act as transmitters, each assigned a unique user code. They encode their sensor readings (the "original audio signal representation") using the ISI-reduction encoding. A central flight control computer acts as the receiver, using the direct conversion module and decoder from Claim 1 to simultaneously receive data from all sensors. The use of CDMA ensures that critical sensor data packets do not interfere with each other, providing a robust, lightweight alternative to a wired CAN bus.

Diagram:

erDiagram
    SENSOR ||--o{ DATA_PACKET : sends
    DATA_PACKET {
        string unique_user_code "CDMA Code"
        string encoded_data "ISI-Reduced Sensor Reading"
    }
    FLIGHT_COMPUTER ||--| DATA_PACKET : receives

Derivative 3.2: AgTech - Livestock Biometric Monitoring

Enabling Description: Each animal in a large herd is fitted with a low-power transmitter tag. This tag integrates sensors for temperature, heart rate, and movement. The sensor data stream is treated as the "original audio signal representation." Each tag has a unique CDMA user code. A central receiver, mounted on a drone or a high point in the pasture, continuously scans for these codes. It can receive and decode packets from thousands of animals simultaneously, as claimed in Claim 1, appearing "virtually free from interference." This allows for early detection of illness or distress across the entire herd.

Diagram:

flowchart LR
    subgraph Animal_1
        A1[Sensors] --> T1{Transmitter w/ Code_1}
    end
    subgraph Animal_2
        A2[Sensors] --> T2{Transmitter w/ Code_2}
    end
    subgraph Animal_N
        A3[Sensors] --> T3{Transmitter w/ Code_N}
    end
    T1 --> R[Central Receiver]
    T2 --> R
    T3 --> R
    R --> D{Decoder}
    D -- Code_1 --> Data_1[Animal 1 Biometrics]
    D -- Code_2 --> Data_2[Animal 2 Biometrics]
    D -- Code_N --> Data_N[Animal N Biometrics]

Axis 4: Integration with Emerging Tech

Derivative 4.1: AI-Enhanced Adaptive Fuzzy Logic Receiver

Enabling Description: The fuzzy logic detection sub-system (61) described in the patent is enhanced with a lightweight, on-device machine learning model (e.g., a tiny neural network). This model runs on the receiver's DSP. It continuously analyzes the characteristics of the received signal, including signal-to-noise ratio, multipath fading, and the specific interference patterns in the user's current environment. The AI model then dynamically rewrites the "if-then" rules of the fuzzy set membership function (as shown in FIG. 4) in real-time to optimize the detection of the user code bits. This adaptive system "learns" its RF environment and provides significantly better performance than a system with static fuzzy logic rules.

Diagram:

graph TD
    A[Received Signal] --> B{Feature Extraction};
    B --> C[AI Model];
    C --> D{Generate/Update Fuzzy Rules};
    B --> E{Fuzzy Logic Detector};
    D --> E;
    E --> F[Detected User Code Bits];

Derivative 4.2: IoT-Enabled Asset Tracking and Communication

Enabling Description: The transmitter and receiver are re-imagined as nodes in an industrial IoT network for asset tracking and operator communication in a warehouse. Each "transmitter" is a tag attached to a pallet or forklift, broadcasting its ID and status using its unique CDMA code. The "receivers" are gateways placed throughout the facility. An operator's headset is also a receiver. This creates a dual-purpose network: the gateways track asset locations, while the operator can select a specific asset's "channel" (CDMA code) to listen for diagnostic alerts or communicate with a sensor on that specific asset, all without interference. The entire system is managed via a cloud dashboard that receives data from the IoT gateways.

Diagram:

sequenceDiagram
    participant Asset_Tag
    participant IoT_Gateway
    participant Cloud_Platform
    participant Operator_Headset
    Asset_Tag->>IoT_Gateway: Broadcasts Status (CDMA Code 123)
    IoT_Gateway->>Cloud_Platform: Forwards Asset 123 Location
    Operator_Headset->>IoT_Gateway: Request Audio from Asset 123
    IoT_Gateway->>Operator_Headset: Streams Audio for CDMA Code 123

Axis 5: The "Inverse" or Failure Mode

Derivative 5.1: Graceful Degradation Low-Power Mode

Enabling Description: A "low-power" mode is implemented for when the battery in either the transmitter or receiver falls below a 15% threshold. When the transmitter battery is low, it sends a specific control packet to the receiver. Upon sending or receiving this packet, both devices enter a reduced-functionality state. The complex "reduced intersymbol interference coding" is bypassed in favor of a simpler, less computationally intensive line code (e.g., Manchester code). The audio is down-sampled to a lower quality (e.g., 22 kHz mono instead of 44.1 kHz stereo) to reduce the processing load on the ADC/DAC and encoders. This extends the remaining operational time by up to 50%, albeit at a reduced audio fidelity.

Diagram:

stateDiagram-v2
    state "High Power Mode (Full Fidelity)" as High
    state "Low Power Mode (Reduced Fidelity)" as Low
    [*] --> High
    High --> Low: Battery < 15%
    Low --> High: Charging
    Low --> [*]: Battery Depleted

II. Combination Prior Art with Open-Source Standards

Scenario 1: Integration with the WebRTC Standard

Description: The physical and data link layers of the communication system are implemented as described in US 9,107,000 (CDMA, ISI-reduction coding). However, the audio stream itself is formatted and controlled using the open-source WebRTC standard. A transmitter plugs into a computer's USB port, identifies itself as a standard audio device, and captures the audio output from a video conference. It packetizes this audio using RTP (Real-time Transport Protocol) and encapsulates it within the CDMA-modulated packets. The receiver decodes the CDMA signal and passes the RTP packets to a lightweight WebRTC stack that handles jitter buffering and audio rendering. This creates a highly robust wireless headset for VoIP applications in noisy RF environments, leveraging the patent's interference rejection with the open standard's widespread software support.

Scenario 2: Implementation on a RISC-V Microcontroller

Description: The entire digital logic of the receiver—including the Viterbi decoder (66), source decoder (68), and the fuzzy logic sub-system (61)—is implemented as firmware running on an open-source RISC-V (RV32IMC) core. The "reduced intersymbol interference coding" is decoded using a set of custom instructions added to the RISC-V ISA. This creates a fully transparent and verifiable system, where the exact methods for decoding and signal processing are defined in open-source code and hardware description language (Verilog/VHDL), rather than being locked in a proprietary ASIC or DSP. This allows for third-party security audits and academic research into improving the coding schemes.

Scenario 3: Combination with the open-source Opus Audio Codec

Description: The patent's source encoder (36) and decoder (68) are explicitly replaced with the open-source Opus interactive audio codec. The Opus codec is highly versatile, capable of seamlessly scaling from low-bitrate narrowband speech to high-fidelity stereo music. The transmitter analyzes the incoming audio signal from the headphone jack (82) and dynamically signals the appropriate Opus mode (e.g., 'speech' or 'music') to the receiver within the data packets. The receiver's Opus decoder then applies the correct decoding algorithm. This provides superior audio quality and lower latency compared to generic encoders and makes the system compliant with an IETF standard, enhancing interoperability.