Abstract: A transceiver block for multi-user, duplex, wireless access system architecture called Multi Carrier Frequency Modulated Spread Spectrum System (MC FM SS). Here symbols are transmitted at multiple subcarriers where each subcarrier is FM or phase encoded with the data. The data is spread in time/bandwidth using a pseudo-random (PN) sequence. In one realization the transmission is performed with the guard ring carriers and/or pilot subcarriers of an Orthogonal Frequency and Code Division Multiplexing, OFDM, system carried on the main RF carrier. The MC FM SS transmits the data symbol over N subcarriers, with each subcarrier encoded in frequency or phase. In Variable Spreading Factor Orthogonal Frequency and Code Division Multiplexing, VSF OFDM, by DoCoMo Japan with 1024 (which can increase to e.g. 6144) carriers are proposed in Long Term Evolution (LTE) 4G system in the down link direction and 2 carriers MC DS CDMA are used in the uplink direction.

Abstract: An air conditioning and heating system includes an condenser, an expansion valve, an evaporator and a compressor interconnected in a closed loop system, and a motor for driving the compressor. The system also includes a refrigerant disposed within the closed loop system. The compressor compresses the refrigerant and pumps the refrigerant through the system. The system also includes one or more feedback loops to reduce the temperature (pre-cool) the refrigerant before it reaches the expansion valve in the cooling mode and the same or a different heat exchanger in the heating mode. The additional heat exchangers are placed in the loop to reduce the electric energy being used.

Abstract: A system and method for constructing a transmitter and a receiver that communicate using multiple orthogonal frequencies which are locked to each other. The set of available frequencies can range from 7, 32 frequencies to a much larger set of frequencies. The transmitted frequencies are separated by a small limited bandwidth (B.W). multiple frequencies are selected from a set of available frequencies and transmitted simultaneously to the receiver. The data transmission is preceded by a calibration sequence where the shift between the transmitted frequency and the frequency measured by fast Fourier transform at the receiver system contain encoders and decoders that convert binary numbers to frequency combinations and the reverse. This transceiver system is capable of transmitting large data rate per unit of a bandwidth e.g. 6 Mbps/3.2 MHZ.

Abstract: Apparatus and methods for data demodulation in FM-FSK communication systems may include comparing the power spectral density (PSD) of the received frequency spectrum with that of the previously received samples using digital signal processing on a multi-sample message. A narrow band FM-FSK receiver may include a filter configured to pass FM signal components of a predetermined signal band, a memory configured to store the filtered signal component, and a DSP operably connected to the filter and the memory. The DSP may be configured to output a digital signal based upon a comparison of successive DSP calculated frequencies associated with a peak power of a power spectrum density (PSD) of successive samples of the filtered multi-sample message.

Abstract: An air conditioning and heating system includes an condenser, an expansion valve, an evaporator and a compressor interconnected in a closed loop system, and a motor for driving the compressor. The system also includes a refrigerant disposed within the closed loop system. The compressor compresses the refrigerant and pumps the refrigerant through the system. The system also includes one or more feedback loops to reduce the temperature (pre-cool) the refrigerant before it reaches the expansion valve in the cooling mode and the same or a different heat exchanger in the heating mode. The additional heat exchangers are placed in the loop to reduce the electric energy being used.

Abstract: A system and method for constructing a transmitter and a receiver that communicate using multiple orthogonal frequencies which are locked to each other. The set of available frequencies can range from 7, 32 frequencies to a much larger set of frequencies. The transmitted frequencies are separated by a small limited bandwidth (B.W). multiple frequencies are selected from a set of available frequencies and transmitted simultaneously to the receiver. The data transmission is preceded by a calibration sequence where the shift between the transmitted frequency and the frequency measured by fast Fourier transform at the receiver system contain encoders and decoders that convert binary numbers to frequency combinations and the reverse. This transceiver system is capable of transmitting large data rate per unit of a bandwidth e.g. 6 Mbps/3.2 MHZ.

Abstract: Apparatus and methods for data demodulation in FM-FSK communication systems may include comparing the power spectral density (PSD) of the received frequency spectrum with that of the previously received samples using digital signal processing on a multi-sample message. A narrow band FM-FSK receiver may include a filter configured to pass FM signal components of a predetermined signal band, a memory configured to store the filtered signal component, and a DSP operably connected to the filter and the memory. The DSP may be configured to output a digital signal based upon a comparison of successive DSP calculated frequencies associated with a peak power of a power spectrum density (PSD) of successive samples of the filtered multi-sample message.

Abstract: A system and method for improving radio communication of frequency or phase modulated transmission and reception. Signal transmission is implemented by suppression of the upper and lower sidebands of a narrowband or very narrowband FM/PM signal from the transmission medium such that transmission is limited to the instantaneous frequency varied about the carrier frequency (center frequency). Suppression may be achieved by adding a bandpass filter between the modulator and the power amplifier of the narrowband FM transmitter. Upon receipt of the suppressed sideband signal, the received signal is converted to a first narrowband IF signal, and then the narrowband or very narrowband frequency deviation IF signal is expanded by frequency multiplication to generate a second wideband or very wideband IF signal. A discriminator may be used to convert the frequency-multiplied signal into a low frequency signal or audio signal for further processing.

Abstract: A system and method for improving radio communication of frequency or phase modulated transmission and reception. Signal transmission is implemented by suppression of the upper and lower sidebands of a narrowband or very narrowband FM/PM signal from the transmission medium such that transmission is limited to the instantaneous frequency varied about the carrier frequency (center frequency). Suppression may be achieved by adding a bandpass filter between the modulator and the power amplifier of the narrowband FM transmitter. Upon receipt of the suppressed sideband signal, the received signal is converted to a first narrowband IF signal, and then the narrowband or very narrowband frequency deviation IF signal is expanded by frequency multiplication to generate a second wideband or very wideband IF signal. A discriminator may be used to convert the frequency-multiplied signal into a low frequency signal or audio signal for further processing.

Abstract: The present system increases the number of channels in a given communication band by using narrow or very narrow band frequency modulation (FM) or phase modulation (PM). The system also improves sound quality, increases the signal-to-noise ratio, increases the power of the transmitted information, and/or achieves high selectivity, high fidelity and/or low distortion. Narrow band FM or PM signal communication can be implemented by transmitting a signal with a narrow or very narrow frequency spectrum, receiving the signal, converting the received signal to an IF (intermediate frequency) signal, and then expanding the narrow frequency deviation of the FM or PM signal. The narrow band frequency deviation may be expanded by frequency-multiplying the IF signal. A discriminator may then convert the frequency-deviation-multiplied signal to a low frequency signal or audio signal for further processing.