Abstract: A discrete multitone stacked-carrier spread spectrum communication method is based on frequency domain spreading including multiplication of a baseband signal by a set of superimposed, or stacked, complex sinusoid carrier waves. In a preferred embodiment, the spreading involves energizing the bins of a large Fast Fourier transform (FFT). This provides a considerable savings in computational complexity for moderate output FFT sizes. Point-to-multipoint and multipoint-to-multipoint (nodeless) network topologies are possible. A code-nulling method is included for interference cancellation and enhanced signal separation by exploiting the spectral diversity of the various sources. The basic method may be extended to include multielement antenna array nulling methods for interference cancellation and enhanced signal separation using spatial separation. Such methods permit directive and retrodirective transmission systems that adapt or can be adapted to the radio environment.

Abstract: A discrete multitone stacked-carrier spread spectrum communication method is based on frequency domain spreading including multiplication of a baseband signal by a set of superimposed, or stacked, complex sinusoid carrier waves. In a preferred embodiment, the spreading involves energizing the bins of a large Fast Fourier transform (FFT). This provides a considerable savings in computational complexity for moderate output FFT sizes. Point-to-multipoint and multipoint-to-multipoint (nodeless) network topologies are possible. A code-nulling method is included for interference cancellation and enhanced signal separation by exploiting the spectral diversity of the various sources. The basic method may be extended to include multielement antenna array nulling methods for interference cancellation and enhanced signal separation using spatial separation. Such methods permit directive and retrodirective transmission systems that adapt or can be adapted to the radio environment.

Abstract: A discrete multitone stacked-carrier spread spectrum communication method is based on frequency domain spreading including multiplication of a baseband signal by a set of superimposed, or stacked, complex sinusoid carrier waves. In a preferred embodiment, the spreading involves energizing the bins of a large Fast Fourier transform (FFT). This provides a considerable savings in computational complexity for moderate output FFT sizes. Point-to-multipoint and multipoint-to-multipoint (nodeless) network topologies are possible. A code-nulling method is included for interference cancellation and enhanced signal separation by exploiting the spectral diversity of the various sources. The basic method may be extended to include multielement antenna array nulling methods for interference cancellation and enhanced signal separation using spatial separation. Such methods permit directive and retrodirective transmission systems that adapt or can be adapted to the radio environment.

Abstract: A fixed wireless system (FWS) utilizing Orthogonal Frequency Division Multiplexing (OFDM) communication techniques is spectrally efficient and responsive to communications involving both voice and high speed data, such as Internet data. The FWS includes a wireless base unit; a plurality of fixed wireless remote units; a plurality of wireless data traffic channels available between the wireless base unit and the plurality of fixed wireless remote units; and a plurality of wireless voice traffic channels available between the wireless base unit and the plurality of fixed wireless remote units. Each wireless traffic channel is identifiable by a unique combination of frequency and time slots. Each wireless data traffic channel is used for carrying high speed data in addressed data packets to and from the plurality of fixed wireless remote units.

Abstract: A method and an apparatus provide for controlled access to a shared communication medium. Time slots on a forward channel include information regarding status useful for remote units to determine whether a reverse channel is available for seizure. Additionally, information along the forward channel provides guidance to the remote units to control attempts to seize the reverse channel. In one embodiment a remote unit divides a data package into a plurality of portions and attempts to seize the reverse channel using a single portion of the data package which corresponds to one time slot on the reverse channel. It then waits until it receives notification along the forward channel that the first data portion was successfully received before it attempts to send any of the remainder of its data in consecutive time slots on the reverse channel.

Abstract: The high quality PCS communications are enabled in environments where adjacent PCS service bands operate with out-of-band harmonics that would otherwise interfere with the system's operation. The highly bandwidth-efficient communications method combines a form of time division duplex (TDD), frequency division duplex (FDD), time division multiple access (TDMA), orthogonal frequency division multiplexing (OFDM), spatial diversity, and polarization diversity in various unique combinations. The method provides excellent fade resistance. The method enables changing a user's available bandwidth on demand by assigning additional TDMA slots during the user's session.

Abstract: A method of operating a communication system is disclosed. The method includes transmitting from a remote unit to a base station remote unit channel data. The remote unit channel is generated at the remote unit and includes data about a first portion of communication channels on which the call can be executed. The method also includes applying a channel selection method to the remote unit channel data and to base station channel data so as to select a communication channel from among the first portion of communication channels. The base station channel data is generated at the base station and includes data about a second portion of the communication channels. The method further includes executing a call on the selected communication channel.

Abstract: A wireless communication system having a base unit and a plurality of remote transceiver units utilizes a dynamic time slot assignment scheme for channel access. The base unit receives and processes a channel access request message from a remote transceiver unit and prepares a channel measurement request message in response. If an Mth time slot of a time frame is available, the base unit sends this message in the Mth time slot and receives a message having channel measurement data in the Mth time slot of the next time frame. On the other hand, if the Mth time slot of the time frame is already reserved, the base unit sends the message in an Nth time slot of the time frame and receives a message having the channel measurement data in the Nth time slot of the next time frame. The base unit selects, based on the channel measurement data, an appropriate channel for communication for the remote transceiver unit.

Abstract: A method is provided for minimizing the peak power level in a combination of orthogonal frequency division multiplexed (OFDM) tones. The method is particularly effective when the information to be communicated is digital data consisting of long patterns of “1”s or “0”s. The digital data of the message is combined with a scrambling vector before the data is modulated. The randomization of data patterns, in turn, leads to a more random combination of OFDM tone amplitude being transmitted. The message is recovered at the receiver by removing the scrambling vector. A table of scrambling vectors is maintained at the transmitters and receivers. The table pointer to select the scrambling vector is selected in response to the position of the message in the communication structure. An OFDM communication system using the above-described method is also provided.

Abstract: The high quality PCS communications are enabled in environments where adjacent PCS service bands operate with out-of-band harmonics that would otherwise interfere with the system's operation. The highly bandwidth-efficient communications method combines a form of time division duplex (TDD), frequency division duplex (FDD), time division multiple access (TDMA), orthogonal frequency division multiplexing (OFDM), spatial diversity, and polarization diversity in various unique combinations. The method provides excellent fade resistance. The method enables changing a user's available bandwidth on demand by assigning additional TDMA slots during the user's session.

Abstract: In a discrete tone system, a base station receives a transmission burst from a remote unit being installed that includes delay compensation pilot tones that are uniformly spread throughout the transmission bandwidth. The arrival time transmission burst is not synchronized with the other remote units transmitting to the base station. The base station measures the phase delay of each tone and calculates the delay of the remote unit from the slope of the line of phase angle versus tone frequency. The base station transmits a signal to the remote unit that includes the magnitude and direction of the delay, which allows the remote unit to adapt the timing of its transmission to be synchronized with the other remote units.

Abstract: A wireless communication system having a base unit and a plurality of remote transceiver units utilizes a dynamic time slot assignment scheme for channel access. The base unit receives and processes a channel access request message from a remote transceiver unit and prepares a channel measurement request message in response. If an Mth time slot of a time frame is available, the base unit sends this message in the Mth time slot and receives a message having channel measurement data in the Mth time slot of the next time frame. On the other hand, if the Mth time slot of the time frame is already reserved, the base unit sends the message in an Nth time slot of the time frame and receives a message having the channel measurement data in the Nth time slot of the next time frame.

Abstract: A method of operating a communication system is disclosed. The method includes transmitting from a remote unit to a base station remote unit channel data. The remote unit channel is generated at the remote unit and includes data about a first portion of communication channels on which the call can be executed. The method also includes applying a channel selection method to the remote unit channel data and to base station channel data so as to select a communication channel from among the first portion of communication channels. The base station channel data is generated at the base station and includes data about a second portion of the communication channels. The method further includes executing a call on the selected communication channel.

Abstract: A method is provided for minimizing the peak power level in a combination of orthogonal frequency division multiplexed (OFDM) tones. The method is particularly effective when the information to be communicated is digital data consisting of long patterns of “1”s or “0”s. The digital data of the message is combined with a scrambling vector before the data is modulated. The randomization of data patterns, in turn, leads to a more random combination of OFDM tone amplitude being transmitted. The message is recovered at the receiver by removing the scrambling vector. A table of scrambling vectors is maintained at the transmitters and receivers. The table pointer to select the scrambling vector is selected in response to the position of the message in the communication structure. An OFDM communication system using the above-described method is also provided.

Abstract: In a discrete tone system, a base station receives a transmission burst from a remote unit being installed that includes delay compensation pilot tones that are uniformly spread throughout the transmission bandwidth. The arrival time transmission burst is not synchronized with the other remote units transmitting to the base station. The base station measures the phase delay of each tone and calculates the delay of the remote unit from the slope of the line of phase angle versus tone frequency. The base station transmits a signal to the remote unit that includes the magnitude and direction of the delay, which allows the remote unit to adapt the timing of its transmission to be synchronized with the other remote units.

Abstract: A distributed radio system with multiple transceivers for simulcasting and selective processing of received signals is provided. The distributed radio system includes a plurality of processing elements and radio frequency transmitter elements interconnected by an Ethernet network. The system designates a number of radio frequency transmitter elements to be elements of a radio frequency simulcast set. The system utilizes relatively few frequency channels, and transmits at very low power levels, and thus causes minimal interference with an existing macrocellular environment. When signals transmitted from a mobile unit are detected by multiple radio receivers, the system is able to select a desired radio receiver signal for processing. When selecting a received signal for processing, the system utilizes a distributed processing technique that performs the selection process throughout several levels. The distributed processing utilized by the selection process may be synchronized.

Abstract: A distributed radio system is disclosed. Transmit and receive packets of data are transported over a relatively high-speed multiplexed network, which in one embodiment may be an Ethernet network. The distributed radio system comprises in one embodiment a centrally-located network-level processing unit connected via network connections to one or more intermediate-level processing units. The intermediate-level processing units may be distributed throughout the coverage area. The processing units perform digital signal processing, as well as higher level processing such as signal routing, speech transcoding and proper interfacing to external environments, such as a macrocellular environment. Radio elements are provided that are accurately timed or synchronized, such that the radio elements have their own time base to ensure proper transmission, even when unpredictable network delays occur.

Abstract: A discrete multitone stacked-carrier spread spectrum communication method is based on frequency domain spreading including multiplication of a baseband signal by a set of superimposed, or stacked, complex sinusoid carrier waves. In a preferred embodiment, the spreading involves energizing the bins of a large Fast Fourier transform (FFT). This provides a considerable savings in computational complexity for moderate output FFT sizes. Point-to-multipoint and multipoint-to-multipoint (nodeless) network topologies are possible. A code-nulling method is included for interference cancellation and enhanced signal separation by exploiting the spectral diversity of the various sources. The basic method may be extended to include multielement antenna array nulling methods for interference cancellation and enhanced signal separation using spatial separation. Such methods permit directive and retrodirective transmission systems that adapt or can be adapted to the radio environment.

Abstract: A distributed radio system with multiple transceivers for simulcasting and selective processing of received signals is provided. The distributed radio system includes a plurality of processing elements and radio frequency transmitter elements interconnected by an Ethernet network. The system designates a number of radio frequency transmitter elements to be elements of a radio frequency simulcast set. The system utilizes relatively few frequency channels, and transmits at very low power levels, and thus causes minimal interference with an existing macrocellular environment. When signals transmitted from a mobile unit are detected by multiple radio receivers, the system is able to select a desired radio receiver signal for processing. When selecting a received signal for processing, the system utilizes a distributed processing technique that performs the selection process throughout several levels. The distributed processing utilized by the selection process may be synchronized.

Abstract: The high quality PCS communications are enabled in environments where adjacent PCS service bands operate with out-of-band harmonics that would otherwise interfere with the system's operation. The highly bandwidth-efficient communications method combines a form of time division duplex (TDD), frequency division duplex (FDD), time division multiple access (TDMA), orthogonal frequency division multiplexing (OFDM), spatial diversity, and polarization diversity in various unique combinations. The method provides excellent fade resistance. The method enables changing a user's available bandwidth on demand by assigning additional TDMA slots during the user's session.