Abstract: The present invention employs hierarchical modulation to simultaneously transmit data over different modulation layers using a carrier RF signal. Each modulation layer may be of a higher or lower order than the other modulation layers. Certain embodiments of the present invention may transmit different information on the different modulation layers. Other embodiments of the present invention may use the different layers for processing information differently.

Abstract: A telecommunications device is provided. The telecommunications device comprises a processor configured such that the device sends a first message to a database management component, the first message containing a communications key encrypted by a database management component key. The processor is further configured such that the device receives a second message from the database management component, the second message encrypted by the communications key. The processor is further configured such that, when the device is able to decrypt the second message, the device considers the database management component to be legitimate.

Abstract: The present invention employs hierarchical modulation to simultaneously transmit data over different modulation layers using a carrier RF signal. Each modulation layer may be of a higher or lower order than the other modulation layers. Certain embodiments of the present invention may transmit different information on the different modulation layers. Other embodiments of the present invention may use the different layers for processing different information streams.

Abstract: The present invention employs hierarchical modulation to simultaneously transmit data over different modulation layers using a carrier RF signal. Each modulation layer may be of a higher or lower order than the other modulation layers. Certain embodiments of the present invention may transmit different information on the different modulation layers. Other embodiments of the present invention may use the different layers for processing information differently.

Abstract: One or more relay stations may be employed along a wireless communication access path between an ingress station and an egress station. A logical communication tunnel is established between the ingress and egress stations through any number of intermediate relay stations to handle session flows of PDUs. As PDUs arrive, the ingress station may determine and add scheduling information to the PDUs before they are delivered to the downstream intermediate relay stations or egress stations. The scheduling information is used by the downstream stations to schedule the PDUs for further delivery. The scheduling information may also be used by the egress station to schedule the PDUs for delivery. The scheduling information added to the PDU by the ingress station bears on a QoS class associated with the PDU, a deadline for the egress station to deliver the PDU, or a combination thereof.

Abstract: The present invention employs hierarchical modulation to simultaneously transmit data over different modulation layers using a carrier RF signal. Each modulation layer may be of a higher or lower order than the other modulation layers. Certain embodiments of the present invention may transmit different information on the different modulation layers. Other embodiments of the present invention may use the different layers for processing different information streams.

Abstract: A mobile relay system for supporting communications between a fixed station and mobile terminals comprising a plurality of mobile relay stations that are associated with each other and provided on a moving platform, wherein each of the plurality of mobile relay stations is capable of facilitating communications with mobile terminals within communication range and at least one of the plurality of mobile relay stations is further capable of facilitating communications with a fixed station within communication range of the at least one of the plurality of mobile relay stations.

Abstract: One or more relay stations may be employed along a wireless communication access path between an ingress station and an egress station. A logical communication tunnel is established between the ingress and egress stations through any number of intermediate relay stations to handle session flows of PDUs. As PDUs arrive, the ingress station may determine and add scheduling information to the PDUs before they are delivered to the downstream intermediate relay stations or egress stations. The scheduling information is used by the downstream stations to schedule the PDUs for further delivery. The scheduling information may also be used by the egress station to schedule the PDUs for delivery. The scheduling information added to the PDU by the ingress station bears on a QoS class associated with the PDU, a deadline for the egress station to deliver the PDU, or a combination thereof.

Abstract: One or more relay stations may be employed along a wireless communication access path between an ingress station and an egress station. A logical communication tunnel is established between the ingress and egress stations through any number of intermediate relay stations to handle session flows of PDUs. As PDUs arrive, the ingress station may determine and add scheduling information to the PDUs before they are delivered to the downstream intermediate relay stations or egress stations. The scheduling information is used by the downstream stations to schedule the PDUs for further delivery. The scheduling information may also be used by the egress station to schedule the PDUs for delivery. The scheduling information added to the PDU by the ingress station bears on a QoS class associated with the PDU, a deadline for the egress station to deliver the PDU, or a combination thereof.

Abstract: A method and apparatus are provided for selecting and signalling the identity of sub-carriers to be used for transmission of data in a radio communication system, and for using other sub-carriers. A remote unit determines which sub-carriers are acceptable for use in data transmission by comparing the signal to interference ratio of each sub-carrier with a threshold. A sequence of numbers is generated using one set of values to identify acceptable sub-carriers and another set of values to identify unacceptable sub-carriers. The sequence of numbers is transmitted to a base station. The average signal to interference ratio of sub-carriers whose signal to interference ratio was above the threshold can also be transmitted to the base station, thereby allowing the base station to determine an optimum set of transmission parameters for use only in the acceptable sub-carriers. Alternatively, the remote unit can determine the optimum set of transmission parameters itself for transmission to the base station.

Abstract: The present invention employs hierarchical modulation to simultaneously transmit data over different modulation layers using a carrier RF signal. Each modulation layer may be of a higher or lower order than the other modulation layers. Certain embodiments of the present invention may transmit different information on the different modulation layers. Other embodiments of the present invention may use the different layers for processing different information streams.

Abstract: The present invention employs hierarchical modulation to simultaneously transmit data over different modulation layers using a carrier RF signal. Each modulation layer may be of a higher or lower order than the other modulation layers. Certain embodiments of the present invention may transmit different information on the different modulation layers. Other embodiments of the present invention may use the different layers for processing information differently.

Abstract: Wireless communication is improved by simultaneously transmitting signals that are orthogonal to received signals. This technique is referred to as Orthogonal Division Duplexing or ODD. Channel characteristics may be estimated based on an analysis of the received signals. Subsequently, techniques used in the transmitting of signals may be adjusted based on the estimated channel characteristics. By using interleaved pilot sub-carriers, each end of a communications link may take measurements of channel conditions. These measurements may be used to adapt the transmission techniques used in the transmitter to the measured channel conditions. Advantageously, this adaptation can occur without the delay in reporting conditions that is characteristic of traditional adaptive communications systems.

Abstract: A method and apparatus are provided for error correction in a communication system employing Orthogonal Frequency Division Multiplexing. When a remote unit receives an OFDM symbol, a retransmission indicator bit is examined to determine whether the symbol is an original symbol or a retransmitted symbol. If it is a retransmitted symbol and the remote unit has a corresponding symbol stored in memory, then the received symbol is soft-combined with the stored symbol. Each packet in the symbol, either the received symbol if original or the soft-combined symbol if retransmitted, is examined by the remote unit. If the remote unit determines that a particular packet is intended for the remote unit, but can not determine the contents of the payload of the packet, the remote unit sends a retransmission request to the base station for retransmission of the symbol.

Abstract: It is becoming increasingly important to improve data throughput in wireless networks. By transmitting data simultaneously at different modulation amplitudes and/or using different code strengths, terminals having different carrier to noise ratios are able to decode the different amplitude levels with varying degrees of success. This allows distant terminals to receive low data rate transmissions at high modulation levels or code rates while nearer terminals can use additional capacity in the transmission by receiving lower level modulation signals or code rates. In this way, distant terminals do not degrade overall network performance. By arranging for terminals to acknowledge receipt of data, retransmission at different modulation levels or code rates may be carried out by the base station in order to improve performance in the presence of noise without a priori knowledge of the carrier to noise ratio for a particular terminal.

Abstract: The present invention relates to a method and apparatus for reducing interference arising from signal propagation delay in multipath signal environments in wireless communication systems. The present invention provides a method of operating a mobile communications base station which receives multipath components of signals from a number of high mobility subscriber terminals, the method comprising: for each subscriber terminal signal received, determining a best signal component; determining the difference in time between reception of said best signal component and a reference time; transmitting to said terminal a transmission timing offset in order to receive said best component at substantially said reference time.

Abstract: A method and apparatus are provided for error correction in a communication system employing Orthogonal Frequency Division Multiplexing. When a remote unit receives an OFDM symbol, a retransmission indicator bit is examined to determine whether the symbol is an original symbol or a retransmitted symbol. If it is a retransmitted symbol and the remote unit has a corresponding symbol stored in memory, then the received symbol is soft-combined with the stored symbol. Each packet in the symbol, either the received symbol if original or the soft-combined symbol if retransmitted, is examined by the remote unit. If the remote unit determines that a particular packet is intended for the remote unit, but can not determine the contents of the payload of the packet, the remote unit sends a retransmission request to the base station for retransmission of the symbol.

Abstract: A method and apparatus are provided for selecting and signalling the identity of sub-carriers to be used for transmission of data in a radio communication system, and for using other sub-carriers. A remote unit determines which sub-carriers are acceptable for use in data transmission by comparing the signal to interference ratio of each sub-carrier with a threshold. A sequence of numbers is generated using one set of values to identify acceptable sub-carriers and another set of values to identify unacceptable sub-carriers. The sequence of numbers is transmitted to a base station. The average signal to interference ratio of sub-carriers whose signal to interference ratio was above the threshold can also be transmitted to the base station, thereby allowing the base station to determine an optimum set of transmission parameters for use only in the acceptable sub-carriers. Alternatively, the remote unit can determine the optimum set of transmission parameters itself for transmission to the base station.

Abstract: A radio system employing Orthogonal Frequency Division Multiplexed (OFDM) includes a Base Transceiver Station (BTS) along with a number of mobile terminals located within a coverage area of the BTS. In this system, a target mobile terminal is provided with a focused transmission beam to receive high data rate traffic information while the remainder of the mobile terminals are provide with pilot and signalling information. To achieve both objectives, a BTS is implemented with a transmission apparatus that generates a directional transmission beam for the data traffic information. In one design, this directional beam transmits the pilot and signalling information along with the data traffic information by rotating the beam within the coverage area. In another design, the BTS has a transmission apparatus that generates more than one transmission beam.

Abstract: An RF radio receiver utilizing wideband RF technology, a wideband digital IF (channelizer) tuner, a common digitizing rate, and multi-user detection (MUD) processes a superposed RF signal to allow simultaneous reception of two or more RF signals sharing overlapping frequency spectrum (RF bandwidth). The RF radio receiver is particularly effective for two or more RF signals of differing RF channel bandwidth and can also receive signals which accord to different air interface standards. The use of a common digitizing rate provides for oversampling of at least one of the RF signals for more accurate decoding and allows for a synchronized signal (i.e. at a common rate) to be used in decoding, and in particular multi-user decoding of other RF signals.