摘要:
A method for contention-based (CB) uplink transmission in a wireless communication network is provided. A base station (eNB) first transmits CB configuration information and CB grant to a user equipment (UE). The UE derives a plurality of transmission opportunities from the uplink CB grant and in response transmits uplink CB data via one of the transmission opportunities. The UE then receives an acknowledgment from the serving base station. If the uplink CB data is non-decodable by the eNB due to multiple contention UEs, then the UE retransmits the uplink data in response to a negative acknowledgment. In one novel aspect, the uplink transmission radio resource carriers both the uplink CB data and UE-selected signature information. In one embodiment, the UE-selected signature information is transmitted via pilot tones. By eliminating a separate phase of contention resolution, the overall latency of CB transmission is reduced and transmission efficiency is improved.
摘要:
A method for contention-based (CB) uplink transmission in a wireless communication network is provided. A base station (eNB) first transmits CB configuration information and CB grant to a user equipment (UE). The UE derives a plurality of transmission opportunities from the uplink CB grant and in response transmits uplink CB data via one of the transmission opportunities. The UE then receives an acknowledgment from the serving base station. If the uplink CB data is non-decodable by the eNB due to multiple contention UEs, then the UE retransmits the uplink data in response to a negative acknowledgment. In one novel aspect, the uplink transmission radio resource carriers both the uplink CB data and UE-selected signature information. In one embodiment, the UE-selected signature information is transmitted via pilot tones. By eliminating a separate phase of contention resolution, the overall latency of CB transmission is reduced and transmission efficiency is improved.
摘要:
A method of managing multiple timing advance (TA) groups, maintaining multiple TA timers, and performing UL synchronization in a multi-carrier wireless system is provided. When a new component carrier (CC) is configured, it is assigned to a TA group having a TA group identifier. The TA groups are managed statically or dynamically. The TA group identifier is used to uniquely identify the TA group in the operations of uplink (UL) timing synchronization. Multiple TA timers are assigned to multiple TA groups. The TA timers may have different values for different TA group. Different embodiments of UL timing adjustments for multiple TA groups are provided.
摘要:
A method of managing multiple timing advance (TA) groups, maintaining multiple TA timers, and performing UL synchronization in a multi-carrier wireless system is provided. When a new component carrier (CC) is configured, it is assigned to a TA group having a TA group identifier. The TA groups are managed statically or dynamically. The TA group identifier is used to uniquely identify the TA group in the operations of uplink (UL) timing synchronization. Multiple TA timers are assigned to multiple TA groups. The TA timers may have different values for different TA group. Different embodiments of UL timing adjustments for multiple TA groups are provided.
摘要:
A contention-based multi-antenna access request transmission/receiving procedure in MIMO OFDM/OFDMA systems is provided to reduce access latency. A mobile station encodes and transmits an access request over a shared access channel using multiple transmitting antennas, while a base station receives and decodes a number of access requests using multiple receiving antennas. Each access request comprises an access indictor and an access message. In a first MIMO scheme, the mobile station transmits the access indicator as preambles, while the access message is encoded by SFBC/STBC to obtain spatial diversity. At the receive side, the access indicator is exploited as pilots for channel estimation. The access message is decoded using SFBC/STBC decoding algorithm. In a second MIMO scheme, the mobile station performs precoding/beamforming for each of the transmitting antenna to obtain beamforming gain, while the base station performs virtual beam matching based on the detection results of the access indicators.
摘要:
Signaling methods for UE-specific downlink control channels in OFDMA systems are provided. In a first method, a dynamic downlink signaling in cell-specific radio resources is used to signal UE-specific downlink control channel in UE-specific radio resources. In LTE, a specific DCI format in PDCCH is used to dynamically signal the UE-specific downlink control channel X-PDCCH that resides in legacy PDSCH region. In a second method, a semi-static higher-layer signaling is used to signal UE-specific downlink control channel in UE-specific radio resources. In LTE, RRC signaling is used to semi-statically signal the UE-specific downlink control channel X-PDCCH that resides in legacy PDSCH region. By using UE-specific downlink control channels, significant control overhead reduction can be achieved.
摘要:
Signaling methods for UE-specific downlink control channels in OFDMA systems are provided. In a first method, a dynamic downlink signaling in cell-specific radio resources is used to signal UE-specific downlink control channel in UE-specific radio resources. In LTE, a specific DCI format in PDCCH is used to dynamically signal the UE-specific downlink control channel X-PDCCH that resides in legacy PDSCH region. In a second method, a semi-static higher-layer signaling is used to signal UE-specific downlink control channel in UE-specific radio resources. In LTE, RRC signaling is used to semi-statically signal the UE-specific downlink control channel X-PDCCH that resides in legacy PDSCH region. By using UE-specific downlink control channels, significant control overhead reduction can be achieved.
摘要:
A method for broadcasting system information via a broadcast channel (BCH) in an OFDMA system is provided. The BCH comprises one or more two-dimensional resource blocks. A plurality of pilot tones and a plurality of data tones are positioned within each resource block. The system information is mapped onto the plurality of data tones. In one embodiment, the plurality of pilot tones are located in configurable positions such that pilot tones of the same resource blocks transmitted by different base stations in the OFDMA system are interlaced to reduce pilot-to-pilot collision. In another embodiment, data tones that are located in pilot positions of other adjacent cells are nullified to reduce data-to-pilot collision. In one novel aspect, the property of interlaced pilot patterns and tone nullification is leveraged to estimate interference second-order statistics, which facilitates receiver implementation and improves receiver performance.
摘要:
A contention-based multi-antenna access request transmission/receiving procedure in MIMO OFDM/OFDMA systems is provided to reduce access latency. A mobile station encodes and transmits an access request over a shared access channel using multiple transmitting antennas, while a base station receives and decodes a number of access requests using multiple receiving antennas. Each access request comprises an access indictor and an access message. In a first MIMO scheme, the mobile station transmits the access indicator as preambles, while the access message is encoded by SFBC/STBC to obtain spatial diversity. At the receive side, the access indicator is exploited as pilots for channel estimation. The access message is decoded using SFBC/STBC decoding algorithm. In a second MIMO scheme, the mobile station performs precoding/beamforming for each of the transmitting antenna to obtain beamforming gain, while the base station performs virtual beam matching based on the detection results of the access indicators.
摘要:
A unified synchronous ranging channel is provided. The unified synchronous ranging channel has a ranging cyclic prefix length that is the same as a cyclic prefix length of a data channel. The unified synchronous ranging channel is used for one of initial ranging, handover ranging, and periodic ranging between a mobile station and a femto base station. In one embodiment, the synchronous ranging channel spans over a two-dimensional radio resource region having a first number of subcarriers along frequency domain, a second number of OFDM symbols along time domain, and a third number of time-domain repetition. At the transmit side, a ranging code sequence is generated by applying a fixed time-domain cyclic shift per OFDM symbol to a root sequence. At the receive side, the ranging code sequence is decoded by using a summation module, a likelihood-combining module, and a modified peak test module that normalizes a peak value.