Patent application number | Description | Published |
20090047971 | Configuring radio resource allocation and scheduling mobile station mechanism for frequency reuse in cellular OFDMA systems - Under adaptive frequency reuse technique, mobile stations in a cellular orthogonal frequency division multiple access (OFDMA) system are served by different radio resource regions with appropriate frequency reuse patterns to mitigate inter-cell interference and improve system capacity. In a first novel aspect, the mobile stations measure interference statistics and obtain interference measurement results. The mobile stations report the obtained interference measurement results to serving base stations. The serving base stations determine adaptive frequency reuse patterns based on the received interference measurement result. In a second novel aspect, a radio resource control element receives the interference measurement results, determines frequency reuse patterns and configures radio resource allocation based on the received interference measurement results. In a third novel aspect, the base stations obtain the interference measurement results and schedule the mobile stations to be served with appropriate radio resource regions. | 02-19-2009 |
20090092059 | Interference measurement mechanism for frequency reuse in cellular OFDMA systems - Under adaptive frequency reuse technique, mobile stations in a cellular orthogonal frequency division multiple access (OFDMA) system are served by different radio resource regions with appropriate frequency reuse patterns to mitigate inter-cell interference and improve system capacity. In a first novel aspect, the mobile stations measure interference statistics and obtain interference measurement results. The mobile stations report the obtained interference measurement results to serving base stations. The serving base stations determine adaptive frequency reuse patterns based on the received interference measurement result. In a second novel aspect, a radio resource control element receives the interference measurement results, determines frequency reuse patterns and configures radio resource allocation based on the received interference measurement results. In a third novel aspect, the base stations obtain the interference measurement results and schedule the mobile stations to be served with appropriate radio resource regions. | 04-09-2009 |
20090185543 | METHODS FOR TRANSMITTING SYSTEM INFORMATION BIT STREAMS AND COMMUNICATION APPARATUSES UTILIZING THE SAME - A method for transmitting system information bit streams of one or more base stations in a wireless communication system is provided. The method includes: identifying network-entry-related bit streams and non-network-entry-related bit streams from the system information bit streams, where the network-entry-related bit streams carry essential system information for a terminal to access a network through at least one of the base stations; modulating the network-entry-related bit streams according to a first set of modulation and coding schemes (MCSs) and modulating the non-network-entry-related bit streams according to a second set of MCSs; and transmitting the system information bit streams with different frequencies, where the network-entry-related bit streams are periodically transmitted according to a first predetermined period. | 07-23-2009 |
20090202010 | SUB-CARRIER ALIGNMENT MECHANISM FOR OFDM MULTI-CARRIER SYSTEMS - A method of aligning sub-carriers of radio signals of two adjacent frequency channels and devices therefor are described. The method comprises aligning a first plurality of sub-carriers of a first radio signal and a second plurality of sub-carriers of a second radio signal within an overlapped frequency region in-between the two adjacent frequency channels by shifting a center frequency of the first radio signal with a frequency offset. The first radio signal and the second radio signal are adapted for transmission over the two adjacent frequency channels and the first frequency channel is one of the two adjacent frequency channels. | 08-13-2009 |
20090274041 | Fast feedback contention-based ranging procedure in wireless communications systems - A fast feedback mechanism is provided in a contention-based ranging procedure. A Subscriber Station (SS) initializes a ranging procedure by sending a ranging code on a selected ranging opportunity for resource access to a Base Station (BS) on a shared ranging channel in a previous uplink frame. The SS also starts a time associated with the ranging code. In response to all received ranging opportunities, the BS broadcasts an acknowledgement (ACK) in a subsequent downlink frame. The ACK comprises a reception status message that indicates the decoding status of the ranging opportunities. With the novel fast feedback mechanism, when ranging collision or failure occurs, upon receiving the reception status report, the SS will proceed with the next round of contention without continuing wait for the entire timeout period. As a result, the total latency due to the ranging collision or failure is reduced. | 11-05-2009 |
20090274096 | Method of network entry in OFDM multi-carrier wireless communications systems - A unified two-stage network entry procedure is provided for OFDM multi-carrier wireless communications systems. During a first stage, a mobile station performs a common network entry procedure using a primary radio frequency carrier and then exchanges multi-carrier capability information with a base station. In one embodiment, the base station transmits a network entry allowance indicator to assist the mobile station in selecting the primary carrier. The network entry allowance indicator comprises information of preference of one or more available carriers. During a second stage, the mobile station enables multi-carrier transmission over multiple frequency channels if both the mobile station and the base station support multi-carrier capability. Before enabling multi-carrier transmission, the mobile station may optionally perform additional ranging by transmitting a ranging request for a secondary carrier. In one embodiment, the base station replies with a ranging response in response to the ranging request through the primary carrier. | 11-05-2009 |
20090310563 | Scanning and handover operation in multi-carrier wireless communications systems - A comprehensive solution is provided for multi-carrier scanning and handover operations in OFDM wireless systems. A multi-carrier scanning is any scanning operation that involves multi-carrier radio frequency carriers. In one embodiment, a mobile station communicates with a serving base station over a primary carrier, and performs scanning over one or more determined carriers. A multi-carrier handover is any handover operation that involves multiple radio frequency carriers. In a first embodiment, a break-before-entry (BBE) handover procedure with fast synchronization is provided. In a second embodiment, an entry-before-break (EBB) handover procedure through unavailable intervals is provided. In a third embodiment, EBB handover procedures for both inter-FA and intra-FA using multiple carriers are provided. Finally, in a fourth embodiment, intra-BS handover procedures are provided. The multi-carrier handover procedures may be applied to 2-to-2 or N-to-N carriers handover situation. The overall scanning time and handover interruption time may be reduced through the provided procedures. | 12-17-2009 |
20100002675 | Method and apparatus of data transmission over guard sub-carriers in multi-carrier OFDM systems - A method of data transmission over guard sub-carriers is provided in a multi-carrier OFDM system. Adjacent radio frequency (RF) carriers are used to carry radio signals transmitted through adjacent frequency channels. A plurality of guard sub-carriers between adjacent frequency channels are aligned and identified for data transmission in a pre-defined physical resource unit. The identified guard sub-carriers do not overlap with normal data sub-carriers of the radio signals transmitted through the adjacent frequency channels. At least one of the identified guard sub-carriers is reserved as NULL sub-carrier. A flexible multi-carrier transceiver architecture is also provided in a multi-carrier OFDM system. Different multi-carrier and/or MIMO/SISO data transmission schemes are implemented by adaptively reconfigure same hardware modules including common MAC layer module, physical layer entities, and RF entities. Furthermore, the flexible multi-carrier transceiver architecture can be used to support data transmission over guard sub-carriers. | 01-07-2010 |