Abstract:
PROBLEM TO BE SOLVED: To reduce power consumption of a mobile station that uses receive diversity. SOLUTION: For determining use of receive diversity in the mobile station, a control system 210 determines a demand level for use of communication resources. A transmitter communicates a message indicating use of receive diversity at a mobile station based on the determined demand level. A receiver 200 receives a channel and determines transmit power level of the channel for being at a lower or upper transmit power level limit. The control system 210 controls receive diversity by selecting a number of receiver chains 290 based on the determined transmit power level. In another aspect, the receiver 200 receives a channel and determines a channel condition of the channel and duration of the channel condition. The control system 210 controls receive diversity by selecting a number of receiver chains 290 based on the determined channel condition and the duration. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To improve use of a forward link by high rate packet data transmission and to decrease a transmission delay in a data communication system capable of variable rate transmission. SOLUTION: Data transmission on the forward link is time multiplexed and a base station transmits at the highest data rate supported by the forward link at each time slot to one mobile station. The data rate is determined by the largest C/I measurement of the forward link signals as measured at the mobile station. Upon determination of a data packet received in error, the mobile station transmits a NACK message back to the base station. The NACK message results in retransmission of the data packet received in error. The data packets can be transmitted out of sequence by the use of sequence number to identify each data unit within the data packets. COPYRIGHT: (C)2009,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide techniques for managing communications in a cellular network.SOLUTION: The cellular network can include one or more sectors in which hotspot carriers are deployed. The hotspot carriers can be available to mobile devices beyond sector boundaries defined by the signal strength of ubiquitous carriers. A mobile device can measure a signal strength of a candidate hotspot carrier and estimate a reverse link mobile device transmit power level for communicating on the hotspot carrier. The mobile device determines whether to add, remove, or maintain the hotspot carrier in its active set on the basis of the estimated transmit power so as to limit interference to the reverse link of non-hotspot sectors.
Abstract:
PROBLEM TO BE SOLVED: To relate to data communication and to provide a new and improved method and apparatus for high rate packet data transmission.SOLUTION: In a data communication system capable of variable rate transmission, high rate packet data transmission improves utilization of the forward link and decreases the transmission delay. Data transmission on the forward link is time multiplexed and the base station transmits at the highest data rate supported by the forward link at each time slot to one mobile station. The data rate is determined by the largest C/I measurement of the forward link signals as measured at the mobile station. Upon determination of a data packet received in error, the mobile station transmits a NACK message back to the base station. The NACK message results in retransmission of the data packet received in error. The data packets can be transmitted out of sequence by the use of sequence number to identify each data unit within the data packets.
Abstract:
PROBLEM TO BE SOLVED: To provide a method and apparatus for quick retransmission of signals in a communication system.SOLUTION: A transmitting terminal transmits signals in a form of packets to a receiving terminal, if the packet is intended for the receiving terminal, if so, the receiving terminal demodulates the packet. The receiving terminal then computes a quality metric of the packet, and compares the computed quality metric with a quality metric contained in the packet. If the quality metrics match, the packet is forwarded for further processing. If the quality metrics fail to match, the receiving terminal sends a request for retransmission of the packet. The transmitting terminal determines which packet needs to be retransmitted based on the request for retransmission. If delivery of the packet in accordance with the description fails, retransmission in accordance with a conventional sequence-number-based scheme, e.g., radio link protocol, is attempted.
Abstract:
PROBLEM TO BE SOLVED: To provide a system for transmitting variable rate data packets. SOLUTION: The data is spread using a long pseudo noise code generated by a linear feedback PN generator 16, the mask of which is selected by mask selector 14 in accordance with the transmission rate of the variable data and the specific user transmitting the data. Thus, by identifying at the receiver which mask will allow the received waveform to be correctly despread, the rate of the data can be determined. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a technique for an improved demodulation process that considers thermal noise for one or more antennas mounted on a receiver, regarding noise variance estimation in wireless communications. SOLUTION: Noise variance estimation includes: receiving a signal including an OFDM symbol having in-band tones including in-band pilot tones and band-edge tones including band-edge pilot tones and guard tones; estimating an equivalent noise variance for the in-band tones using the in-band pilot tones and channel estimates for the in-band pilot tones; and estimating an equivalent noise variance for the band-edge tones using the band-edge pilot tones, channel estimates for the band-edge pilot tones, and the guard tones. COPYRIGHT: (C)2011,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a communication device for providing multimedia in a group communication network. SOLUTION: A system and method for providing group communication services is disclosed. Each of a plurality of group communication devices converts media, such as video, audio, image and/or data into data packets suitable for transmission over a data network, such as the Internet. The data packets are selectively transmitted through the data network to a communications manager. The communications manager acts as a configurable switch, allowing communications from any communication device to be selectively routed to the plurality of communication devices on the basis of the types of the communication devices and/or the requests received form the corresponding users. The communications manager further allows users of other communication systems and devices to participate in group communications with each other. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a transmitter-oriented, distributed receiver using multi-user diversity provided by the distribution of the receiver. SOLUTION: Advantage is taken of uncorrelated variations over time in the condition of communication links between a common transmitter and several users. The greater the variation in the quality of a particular link over time is, the greater the increase in total system throughput provided is. A scheduler metric represents the instantaneous quality of the communication link between each user and the transmitter with respect to the average quality of the link. Alternatively, the scheduler metric represents the instantaneous channel condition with respect to the average data throughput over that channel. A common transmitting station uses the scheduler metric to directly compare the desirability of granting each channel access with the desirability of granting mutual channel access. Users with links having the greatest scheduler metric are allowed to access the channels. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a method and apparatus for tracking signals in a wireless communication system. SOLUTION: In one embodiment, a base station includes a rake antenna having a plurality of fingers. When any of the fingers is unlocked, the base station waits a predetermined time period and then adjusts a lock detecting filter 30. The adjustment is performed based on comparison of received signal energy to an adjusted energy threshold 38. The comparison may result in an increased energy level of the filter. In one embodiment, if a mobile station is in soft hand-off mode, the base station ignores the lock state of the fingers and transmits power control information based on the received signal energy. If the mobile station is not in soft hand-off mode, a predetermined power control pattern is applied for gradual power adjustment. COPYRIGHT: (C)2009,JPO&INPIT