Abstract:
PROBLEM TO BE SOLVED: To provide a method for two or more transmitters to share a single code division multiplex (CDM) system, and code division multiple access (CDMA) system. SOLUTION: A set of orthogonal channelizing codes is generated, and each transmitter is allocated the orthogonal channelizing codes and pseudonoise polynomials in a predetermined manner. The transmitters channelize each user signal using an orthogonal channelizing code, and spread each user signal using a pseudonoise spreading code. Each transmitter employs the same PN (pseudonoise) spreading codes and time offsets. No one orthogonal channelizing code is assigned to more than two transmitters during the time period in which they are sharing a CDM channel. The spread signals are summed at each transmitter prior transmission as a composite signal. The offsets are time-precorrected to ensure time alignment at the receivers. The frequencies of signals are precorrected to ensure frequency alignment at the receivers. COPYRIGHT: (C)2005,JPO&NCIPI
Abstract:
PROBLEM TO BE SOLVED: To provide techniques for mitigating interference in a wireless communication system.SOLUTION: Pertinent transmission parameters for a served UE may be sent to at least one interfered UE to support interference mitigation. In one design, information for at least one transmission parameter for a data transmission sent by a first cell to a first UE may be transmitted to at least one UE served by a second cell to enable at least one UE to perform interference mitigation for the data transmission sent by the first cell to the first UE. A cell may send transmission parameters for a UE via a pilot.
Abstract:
PROBLEM TO BE SOLVED: To provide techniques for flexible bandwidth allocation that reduces interference.SOLUTION: A spectrum may have a first number of segments, each segment having a second number of clusters associated with a certain sector/cell. One aspect comprises the acts of fixedly assigning a first group of clusters to a first group of users such that the first group of users stay fixed to the assigned clusters, and assigning a second group of clusters to a second group of users such that the second group of users hop within the assigned clusters.
Abstract:
PROBLEM TO BE SOLVED: To provide techniques to support soft handoff in a frequency hopping OFDMA system.SOLUTION: To non-handoff users, information channels are assigned by their sole sectors. To soft-handoff users, information channels are assigned by their "serving" sectors. For each sector, the information channels assigned to the non-handoff users are orthogonal to one another and may or may not be orthogonal to the information channels assigned to the soft-handoff users. Each sector processes its received signal and recovers data transmission from the non-handoff users of that sector. Each sector then estimates interference due to the non-handoff users and cancels the interference from the received signal.
Abstract:
PROBLEM TO BE SOLVED: To provide techniques of supporting fast frequency hopping with a code division multiplexed pilot in a multi-carrier communication system.SOLUTION: Each transmitter in the system transmits a wideband pilot on all subbands to allow a receiver to estimate the entire channel response at the same time. The wideband pilot for each transmitter is generated using direct sequence spread spectrum processing and based on a pseudo-random number code assigned to that transmitter. This allows the receiver to individually identify and recover multiple wideband pilots transmitted concurrently by multiple transmitters. For a time division multiplexed/code division multiplexed pilot transmission scheme, each transmitter transmits the wideband pilot in bursts. For a continuous code division multiplexed pilot transmission scheme, each transmitter continuously transmits the wideband pilot, albeit at a low transmit power level.
Abstract:
PROBLEM TO BE SOLVED: To provide techniques for encoding and decoding data.SOLUTION: Multiple code rates for a forward error correction (FEC) code may be supported, and a suitable code rate may be selected based on packet size. A transmitter may obtain at least one threshold to use for code rate selection, determine a packet size to use for data transmission, and select a code rate among the multiple FEC code rates based on the packet size and the at least one threshold. Multiple FEC codes of different types (e.g., Turbo, LDPC, and convolutional codes) may be supported, and a suitable FEC code may be selected based on packet size. The transmitter may obtain at least one threshold to use for FEC code selection and may select an FEC code among the multiple FEC codes based on the packet size and the at least one threshold.
Abstract:
PROBLEM TO BE SOLVED: To multiply pilot symbols to be transmitted from each of a plurality of antenna groups to improve channel estimation for different sectors.SOLUTION: Pilot symbols transmitted from different sectors of the same base station are multiplied using the same cell specific scrambling code as well as a first code having low cross correlation and a second code having low cross correlation. The second code is constant over the length of the first code, but may vary for repetitions of the first code.
Abstract:
PROBLEM TO BE SOLVED: To optimize use of system resources through supplemental assignments for dynamically decrementing resource assignments to mobile devices in a wireless network environment.SOLUTION: A method comprises: transmitting initial resource assignment(s) to at least one mobile device (1002); determining whether the at least one mobile device requires additional resources or requires resource de-allocation (1004); and, if the resource de-allocation is required, generating a supplemental assignment that de-assigns the resources and transmitting the generated supplemental assignment to the at least one mobile device (1006). Supplemental assignments can be generated based on information related to mobile device need and resource availability. Moreover, resource assignments may be retained for a mobile device.
Abstract:
PROBLEM TO BE SOLVED: To provide a method of performing rank step-down for MIMO SCW (single code word) design employing HARQ.SOLUTION: Systems and methods are described that facilitate reducing rank (e.g., of a user device) as a number of transmissions from the user increases. Such rank step-down can improve interference resistance and facilitate maintaining code rate despite transmission propagation. Rank step-down information is encoded along with CQI information to generate a 5-bit CQI signal that can facilitate updating a user's rank upon each CQI transmission (approximately every 5 msec). The described systems and/or methods can be employed in a single code word (SCW) wireless communication environment with a hybrid automatic request (HARQ) protocol.
Abstract:
PROBLEM TO BE SOLVED: To reduce overhead in responding to an ACK/NACK message, in a multiple access system applied to a packet re-transmission mechanism such as an ARQ. SOLUTION: This method is equipped with: reception of data representing ACK or data representing NACK; measurement of quality of the received data; determination of whether a channel is degraded by using the quality measurement value of the received data as a function; neglect of the received data representing ACK or data representing NACK when the channel is determined to be degraded; and transmission of a message representing stop of transmission of the data representing ACK and/or the data representing NACK when the channel degradation is determined and the response to the received data is issued. COPYRIGHT: (C)2011,JPO&INPIT