Mediatek Corporation

Hfi Innovation Inc.

Yu-Hao Chang

Yih-Shen Chen

Ciou-Ping Wu

Pei-Kai Liao

Chien-Hwa Hwang

Chih-Yuan Lin

Chia-Chun Hsu

Kuo-Ming Wu

I-Kang Fu

Methods to manage multiple component carriers (CCs) efficiently in a mobile network with carrier aggregation (CA) enabled are proposed. For CC activation/deactivation, a single LCID value is used to represent both activation and deactivation command. A single command with multiple instructions is provided to activate and/or deactivate multiple CCs. In addition, unnecessary re-activation or re-inactivation of a CC is prevented, and explicit feedback for activation/deactivation is considered. For scheduling mechanism, a novel buffer status reporting (BSR) procedure is provided, where only one BSR is calculated after preparing all the transport blocks (TB) within one transmission time interval (TTI). Novel power headroom reporting (PHR) format and trigger are also provided. For DL-UL linking, various linking types are created based on whether there is carrier indicator field (CIF) in DL grant or UL grant. The various linking types are used in different applications to improve scheduling flexibility and load balancing.

Methods for carrier aggregation

A communications apparatus is provided. A controller module obtains information regarding a Hybrid Automatic Repeat Request (HARQ) round trip time (RTT) in an HARQ process, arranging one or more almost blank sub-frame(s) in one or more frame(s) according to the HARQ RTT information and generating a sub-frame pattern describing the arrangement of the almost blank sub-frame(s), wherein the HARQ RTT is defined by the communications system. A transceiver module transmits at least a signal carrying information regarding the sub-frame pattern to a peer communications apparatus in the communications system. In addition, at least one almost blank sub-frame in the sub-frame pattern is arranged in a sub-frame for the peer communications apparatus to transmit an uplink grant message for granting an user equipment to transmit uplink data to the peer communications apparatus.

Method for coordinating transmissions between different communications apparatuses and communication sapparatuses utilizing the same

A method for coordinating transmissions between different communications apparatuses in a communications system. The method obtains a sub-frame indicator carried in a first control signal transmitted in a control region of a first sub-frame received from an evolved node B (eNB), wherein the sub-frame indicator indicates resource allocation of one or more sub-frame following the first sub-frame. The method then determines whether a second sub-frame following the first sub-frame and received from the eNB is an almost blank sub-frame according to the sub-frame indicator. When the second sub-frame is not the almost blank sub-frame, obtaining information regarding a start position of a data region of the second sub-frame from a second control signal transmitted in a control region of the second sub-frame.

Sounding mechanism for LTE-A systems under carrier aggregation is provided. A UE receives an uplink or downlink grant transmitted from an eNB over a primary carrier in a multi-carrier LTE-A system. The UE determines indicated carrier(s) and detects a triggering condition for aperiodic sounding transmission in the grant. The UE then selects UE-specific sounding reference signal (SRS) parameters. Finally, the UE transmits an aperiodic SRS (ap-SRS) over the indicated carrier(s) using the selected UE-specific SRS parameters. In one embodiment, the uplink or downlink grant is transmitted via a PDCCH carrying various DCI formats. Each DCI format contains a carrier indicator field (CIF) that indicates which carrier is used for ap-SRS transmission if cross-carrier scheduling is enabled. In another embodiment, DCI format 3/3A is transmitted via a PDCCH carrying a plurality of information fields, each field indicates if the UE should enable ap-SRS in a particular carrier.

Sounding mechanism under carrier aggregation

A communications apparatus is provided. A controller module generates a suggested sub-frame pattern describing suggested arrangement of one or more almost blank sub-frame(s) in one or more frame(s) and schedules control signal and/or data transmissions according to the suggested sub-frame pattern. A transceiver module transmits at least a first signal carrying information regarding the suggested sub-frame pattern to a peer communications apparatus. The peer communications apparatus does not schedule data transmissions in the almost blank sub-frame(s).

Method for coordinating transmissions between different communications apparatuses and communications apparatuses utilizing the same

A channel interleaver comprises a novel constellation-based permutation module. The channel interleaver first receives a plurality of sets of encoded bits generated from an FEC encoder. The encoded bits are distributed into multiple subblocks and each subblock comprises a plurality of adjacent bits. A subblock interleaver interleaves each subblock and outputs a plurality of interleaved bits. The constellation-based permutation module rearranges the interleaved bits and outputs a plurality of rearranged bits. The rearranged bits are supplied to a symbol mapper such that a plurality of consecutively encoded bits in the same set of the encoded bits generated from the FEC encoder is prevented to be mapped onto the same level of bit reliability of a modulation symbol. In addition, the plurality of adjacent bits of each subblock is also prevented to be mapped onto the same level of bit reliability to achieve constellation diversity and to improve decoding performance.

Channel interleaver having a constellation-based unit-wise permuation module

Two preamble partition schemes are provided for flexible network deployment and efficient utilization of limited cell identification resources in a wireless network. In a soft partition scheme, the entire preamble sequences are partitioned into several configurable non-overlapping subsets, and each subset is associated with a corresponding cell type. In a hybrid partition scheme, a combination of fixed and configurable subsets is used for preamble partition. The partitioning information is carried in a broadcasting channel broadcasted from base stations to mobile stations. In one embodiment, after a mobile station performs scanning and synchronization with a first base station, it derives the cell type of the first base station from cell identification and partitioning information. The mobile station completes ranging and network entry with the first base station if the cell type is preferred, and starts to perform scanning and synchronization with a second base station if the cell type is non-preferred.

Preamble partition and cell identification procedure in wireless communication systems

A method of power control message indexing is provided in a wireless Orthogonal Frequency Division Multiple Access (OFDMA) network. A base station configures fast feedback channels (FFBCHs) and mobile stations report downlink channel information via the configured FFBCHs. Based on the received channel information, the base station estimates uplink channel quality and detects any channel variation. In response to uplink channel variation, the base station delivers power offsets to adjust the transmit power levels of the mobile stations. In one advantageous aspect, the power control commands for mobile stations are aggregated and the indexing scheme of the power control commands is implicitly based on the configured FFBCHs. For example, if a FFBCH is located at a first location in an uplink frame, then a following power control command in response to the FFBCH is located at a second location in a downlink frame, the second location is located after the first location with a predefined fixed delay time.

Uplink power control message indexing in wireless OFDMA systems

A hierarchical downlink (DL) synchronization channel (SCH) is provided for wireless OFDM/OFDMA systems. The SCH includes a Primary SCH (P-SCH) for carrying PA-Preambles used for coarse timing and frequency synchronization, and a Secondary SCH (S-SCH) for carrying SA-Preambles used for cell ID detection. The total time length occupied by P-SCH and S-SCH is equal to one OFDM symbol time length of a data channel, and S-SCH is located in front of P-SCH in each DL frame. A perfect multi-period time-domain structure is created and maintained in P-SCH to increase preciseness of frame boundary estimation. With overlapping deployment of macrocells and femtocells, a predefined SCH configuration scheme is provided to separate frequency subbands used for macrocells and femtocells such that interferences in S-SCH can be mitigated. In addition, a self-organized SCH configuration scheme is provided to allow more flexibility for femtocells to avoid or introduce interference in S-SCH.

Synchronization channel for advanced wireless OFDM/OFDMA systems

A method of uplink power control in a wireless OFDMA system is provided. A serving base station first configures a fast feedback channel by transmitting a feedback allocation message to a mobile station. The mobile station then reports downlink channel information via the allocated fast feedback channel. Based on the reported downlink channel information, the serving base station estimates uplink channel quality and thereby detects a channel variation and generates an uplink power adjustment message that delivers a power offset to adjust the transmitting power level of the mobile station. In one novel aspect, the uplink power adjustment message also comprises feedback allocation information that re-configures the fast feedback channel without extra signaling overhead. In addition, the novel power adjustment message eliminates redundant information such that it is transmitted via a minimum resource unit without requiring extra resource.

Uplink power control message design in wireless OFDMA systems

Channel interleaver having a constellation-based block-wise permuation module

In advanced wireless OFDMA communication systems, hierarchical synchronization is adopted to synchronize between a base station (BS) and a mobile station (MS). In a hierarchical synchronization architecture, primary advanced preamble (PA-Preamble) is used for coarse time domain synchronization while cell ID is detected using several accumulated secondary advanced preambles (SA-Preambles). Network entry latency can be reduced by adjusting the relative location of superframe header (SFH), PA-Preamble and SA-Preambles within a superframe. Three different synchronization channel (SCH) architectures are proposed to provide different tradeoffs between network entry latency and the robustness of SA-Preamble design and cell ID detection.

Growing community of inventors

Daya, Taiwan

Yu-Hao Chang