摘要:
In an orthogonal frequency division multiple access (OFDMA) system including at least one base station and at least one wireless transmit/receive unit (WTRU), sub-carriers are allocated for data transmissions to multiple access WTRUs, where sub-carriers are allocated according to a consecutive sub-carrier allocation (CSA) type and a distributed sub-carrier allocation (DSA) type. Pilot signals with distributed pilot sub-carriers are transmitted and measured at each WTRU to obtain a channel quality metric for each pilot sub-carrier. Each WTRU sends feedback to the base station reporting channel quality based on the measured channel quality metrics. An allocation type is selected and adaptively switched according to channel variations in time and frequency domain.
摘要:
A receiver sends hybrid automatic repeat request (H-ARQ) feedback for a current packet and at least one previous packet, whereby an error is detected based on the H-ARQ feedback. The receiver sends H-ARQ feedback with an identification of the packet or a sequence number of a packet that the receiver expects to receive next. The receiver stores a packet in a memory before combining the packet with a previously received packet, and decodes the stored packet after failing to decode a combined packet to avoid a corruption error. The receiver may set a timer when sending a NACK. If the receiver fails to receive a packet until expiration of the timer, the receiver initiates a process for recovering the packet. Each H-ARQ feedback may be associated with other attributes. Some H-ARQ processes may operate in an asynchronous mode while others in a synchronous mode in the same direction.
摘要:
A Node-B sends a polling message to a wireless transmit/receive unit (WTRU). The WTRU sends an uplink synchronization burst in response to the polling message without contention. The Node-B estimates an uplink timing shift based on the synchronization burst and sends an uplink timing adjustment command to the WTRU. The WTRU then adjusts uplink timing based on the uplink timing adjustment command. Alternatively, the Node-B may send a scheduling message for uplink synchronization to the WTRU. The WTRU may send a synchronization burst based on the scheduling message. Alternatively, the WTRU may perform contention-based uplink synchronization after receiving a synchronization request from the Node-B. The WTRU may enter an idle state instead of performing a handover to a new cell when the WTRU moves to the new cell. A discontinuous reception (DRX) interval for the WTRU may be set based on activity of the WTRU.
摘要:
A method and apparatus for dynamically configuring a memory for hybrid automatic repeat request (H-ARQ) processes in a receiving node to permit a more flexible H-ARQ memory configuration and improve the performance of H-ARQ processes. An H-ARQ memory in the receiving node is reserved for a plurality of H-ARQ processes. A transmitting node dynamically configures the H-ARQ memory in the receiving node for each H-ARQ transmission so that the memory requirement for a plurality of H-ARQ processes exceeds the H-ARQ memory capacity. If there is insufficient H-ARQ memory available to support H-ARQ transmissions, only a subset of the plurality of H-ARQ processes may be activated at a time. When there is insufficient H-ARQ memory for processing H-ARQ transmissions, a negative acknowledgement (NACK), an acknowledgement (ACK), nothing, and/or information indicating the reason for a failed transmission may be transmitted to a transmitting node.
摘要:
In a wireless communication system comprising at least one evolved Node-B (eNB) and a plurality of wireless transmit/receive units (WRTUs), a non-contention based (NCB) channel is established, maintained, and utilized. The NCB channel is allocated for use by one or more WTRUs in the system for utilization in a variety of functions, and the allocation is communicated to the WTRUs. The wireless communication system analyzes the allocation of the NCB channel as required, and the NCB channel is reallocated as required.
摘要:
The present invention is a method and apparatus for resource allocation signaling for grouping user real time services. Uplink signaling for voice activity reporting of each user's transition between an active state and an inactive voice state is sent from a wireless transmit/receive unit to a Node B. Radio resource allocation to users of a wireless communication system varies based on user measurement reporting, a pre-determined pattern such as frequency hopping, or a pseudorandom function. Grouping methods are adjusted to better utilize the voice activity factor, so that statistical multiplexing can be used to more efficiently utilize physical resources.
摘要:
A method for dynamically updating a random access channel (RACH) configuration is disclosed. One or more RACH configurations, including one or more RACH configuration parameters, in a wireless channel are detected, and the appropriate RACH configuration parameters to use based on a RACH signal.
摘要:
An apparatus and a method for improving packet transmission and reducing latency in VoIP over WLAN using switched beam antennas having multiple directional antenna beams are disclosed. In an access point having a switched beam antenna, or other smart antenna system, the present invention extends the coverage area of an access point for authentication and association of a new WTRU, extends the access points coverage area during in session transmissions with a WTRU, and adjusts data rates. The method also controls Contention Period (CP)/Contention Free Period (CFP) timing amongst beams emanating from an access point having a switched beam antenna, or other smart antenna system. Fast diversity switching, frame level switching, lowered data rates, and scanning multiple directional antenna beams for the optimum transmission beam are disclosed to improve beam selection and packet transmission.
摘要:
A method and apparatus for detecting a radio link (RL) failure for uplink (UL) and downlink (DL) in a long term evolution (LTE) wireless communication system including at least one wireless transmit/receive unit (WTRU) and at least one evolved Node-B (eNodeB) are disclosed. A determination is made as to whether an RL has an in-synchronization status or an out-of-synchronization status. An RL failure is declared if an out-of-synchronization status is detected.
摘要:
In a wireless communication system including a wireless transmit/receive unit (WTRU) and an evolved Node B (eNB) capable of transmitting and receiving wireless data, a method and apparatus for reducing transmission overhead includes receiving an upper layer sequence number (SN). The upper layer SN is converted into a radio link control (RLC) service data unit (SDU) SN (SSN). An RLC protocol data unit (PDU) is generated for transmission including an RLC SSN, and incurred transmission overhead is optimized.