| Patent application number | Description | Published |
|---|
| 20090003466 | System and Method for Mapping Symbols for Mimo Transmission - Methods and devices are provided for MIMO OFDM transmitter and receivers having odd and/even numbers of transmit antennas. Various methods for pre-coding information bits before space time coding (STC) are described for enabling transmission of information bits over all antennas. Methods of decoding received signals that have been pre-coded and STC coded are also provided by embodiments of the invention. Pilot patterns for downlink and uplink transmission between a base station and one or more wireless terminals for three transmit antenna transmitters are also provided. Variable rate codes are provided that combine various fixed rate codes in a manner that results in codes whose rates are dependent on all the various fixed rate codes that are combined. | 01-01-2009 |
| 20090060081 | Systems and methods for ofdm channelization - Systems and methods for OFDM channelization are provided that allow for the co-existence of sub-band channels and diversity channels. Methods of defining diversity sub-channels and sub-band sub-channels are provided, and systematic channel definition and labeling schemes are provided. | 03-05-2009 |
| 20090103494 | SOFT HANDOFF FOR OFDM - The present invention relates to soft handoffs in an OFDM system. Each mobile terminal measures pilot signal strengths of transmissions from adjacent base stations. If the pilot signal strength for a base station exceeds the defined threshold, that base station is added to an active set list. Each mobile terminal notifies the base stations of their active set lists. By providing the set list to the base station controller and the servicing base station, the mobile terminal identifies the sole servicing base station or triggers a soft handoff mode when multiple base stations appear on the active set list. The soft handoff mode uses a combination of scheduling and space-time coding to affect efficient and reliable handoffs. | 04-23-2009 |
| 20090129502 | WIRELESS FEEDBACK SYSTEM AND METHOD - A codebook C is provided in a MIMO transmitter as well as a MIMO receiver. The codebook C will include M codewords c | 05-21-2009 |
| 20090213948 | ADAPTIVE TWO-DIMENSIONAL CHANNEL INTERPOLATION - A method and apparatus for improving channel estimation within an OFDM communication system. Channel estimation in OFDM is usually performed with the aid of pilot symbols. The pilot symbols are typically spaced in time and frequency. The set of frequencies and times at which pilot symbols are inserted is referred to as a pilot pattern. In some cases, the pilot pattern is a diagonal-shaped lattice, either regular or irregular. The method first interpolates in the direction of larger coherence (time or frequency). Using these measurements, the density of pilot symbols in the direction of faster change will be increased thereby improving channel estimation without increasing overhead. As such, the results of the first interpolating step can then be used to assist the interpolation in the dimension of smaller coherence (time or frequency). | 08-27-2009 |
| 20090316802 | MULTI-USER MIMO SYSTEMS AND METHODS - A method is provided for scheduling data transmission in a Multiple-Input Multiple-Output (MIMO) Orthogonal Frequency Division Multiplexing (OFDM) system. The MIMO-OFDM system may comprise at least one MIMO-OFDM transmitter and at least one MIMO-OFDM receiver Feedback from one or more receivers may be used by a transmitter to improve quality, capacity, and scheduling in MIMO-OFDM communication systems. The method may comprise generating or receiving information pertaining to a MIMO channel metric and information pertaining to a Channel Quality Indicator (CQI) in respect of a transmitted signal; and sending a next transmission to a receiver using a MIMO mode selected in accordance with the information pertaining to the MIMO channel metric, and an adaptive coding and modulation selected in accordance with the information pertaining to the CQI. | 12-24-2009 |
| 20100260137 | METHODS AND SYSTEMS FOR CHANNELIZATION - Methods and systems are described that are suitable for channelization, m particular, but not limited to, the IEEE 80216.m telecommunications standard. For a time-frequency resource, physical sub-carriers for each of one or more zones in the time-frequency resource are assigned to one or more zones having a respective type of transmission. At least one zone is allocated for a type of transmission using localized sub-carriers. The physical sub-carriers assigned to each zone are permuted to map to logical sub-carriers—Groups of resource blocks are formed, in which each resource block includes at least one logical sub-carrier for each of the one or more zones. The information defining the groups of resource blocks for each of the one or more zones can then be transmitted to a user. The information may be in the form of a zone configuration index. | 10-14-2010 |
| 20100278123 | WIRELESS COMMUNICATION FRAME STRUCTURE AND APPARATUS - A method comprises providing a frame, the frame including a downlink sub-frame and an uplink sub-frame, portions of the downlink sub-frame and uplink sub-frame being allocated for communication with a mobile station configured to operate utilizing a legacy IEEE 802.16 standard, and portions of the downlink sub-frame and uplink sub-frame being allocated for communication with a mobile station configured to operate utilizing the IEEE 802.16m standard; and using the frame to wirelessly communicate with a mobile station in at least one of the uplink and downlink directions. A method of using an 802.16m frame structure for multi-band operation is also provided, as well as an 802.16m frame structure for relay support. | 11-04-2010 |
| 20100284480 | METHOD AND APPARATUS FOR CHANNEL QUALITY MEASUREMENTS - A method and apparatus are provided for measuring channel quality over which has been transmitted a sequence of symbols produced by encoding and constellation mapping a source data element sequence. The method includes receiving a sequence of received symbols over the channel whose quality is to be measured. The sequence of received symbols is de-mapped based on a first channel quality indicator previously transmitted to a transmitter of the sequence of symbols. The method also includes decoding the de-mapped symbols to produce a decoded output sequence. In some embodiments, the decoding may be based on the first channel quality indicator. The method also includes re-encoding the decoded output sequence to produce a re-encoded output sequence. The method also includes correlating the de-mapped symbols with the re-encoded output sequence to produce a second channel quality indicator. The second channel quality indicator is transmitted to the transmitter to adaptively select a type of mapping based on the second channel quality indicator. In some embodiments, the transmitter may adaptively select a type of encoding based on the second channel quality indicator. | 11-11-2010 |
| 20110041027 | METHODS AND SYSTEMS FOR HARQ PROTOCOLS - Methods described herein are for wireless communication systems. One aspect of the invention is directed to a method for a HARQ process, in which the HARQ process includes a first transmission of an encoder packet and at least one retransmission. The method involves allocating a transmission resource for each respective transmission. The method involves transmitting control information from a base station to a mobile station for each respective transmission. The control information includes information to uniquely identify the HARQ process and an identification of one of a time resource, a frequency resource and a time and frequency resource that is allocated for the transmission. In some embodiments of the invention, specific control information is signalled from a base station to a mobile station to enable RAS-HARQ operation. In some embodiments of the invention, retransmission signaling in included as part of regular unicast signaling used for both first transmission and retransmissions. In some embodiments of the invention, a 3-state acknowledgement channel and associated error recovery operation enables the base station and mobile station to recover from control signaling error and reduce packet loss. | 02-17-2011 |
| 20110086662 | METHODS FOR CONTROL SIGNALING FOR WIRELESS SYSTEMS - To effectively and efficiently provide control information, a broadcast pointer channel (BPCH) may be used to identify the type and perhaps relative location of control information that is being provided in a given frame structure, such as a sub-frame, frame, or superframe. A sub-frame (or like framing entity, such a frame or superframe) may have a BPCH and a corresponding system control information segment in which control information may reside. The system control information segment may have any number of control information blocks, wherein each control information block that is present may correspond to a particular type of control information. The BPCH is used to identify the type of control information that is present in a corresponding system control information segment, and if needed or desired, the relative locations of the various control information. | 04-14-2011 |
| 20110096751 | SOFT HANDOFF FOR OFDM - The present invention relates to soft handoffs in an OFDM system. Each mobile terminal measures pilot signal strengths of transmissions from adjacent base stations. If the pilot signal strength for a base station exceeds the defined threshold, that base station is added to an active set list. Each mobile terminal notifies the base stations of their active set lists. By providing the set list to the base station controller and the servicing base station, the mobile terminal identifies the sole servicing base station or triggers a soft handoff mode when multiple base stations appear on the active set list. The soft handoff mode uses a combination of scheduling and space-time coding to affect efficient and reliable handoffs. | 04-28-2011 |
| 20110122846 | UPLINK CONTROL SIGNAL DESIGN FOR WIRELESS SYSTEM - Transmission of uplink control message for a wireless system. The uplink control message may be encoded according to one of multiple possible schemes. The choice of encoding scheme may be made based on the control message size and/or based on the available transmission resources and/or based on the detection scheme used on the receiving end. A modulation scheme may also be selected based on such factors. CDM may be used for certain control messages. Block code encoding, such as Reed-Muller encoding may be used for certain control messages. Different transmission resources may be allocated for different control message uses. The encoding specifics may be selected to obtain a certain hamming distance and/or size of the encoded message or based on other factors. | 05-26-2011 |
| 20110149846 | UPLINK CONTROL SIGNAL DESIGN FOR WIRELESS SYSTEM - Transmission of uplink control message for a wireless system. The uplink control message may be encoded according to one of multiple possible schemes. The choice of encoding scheme may be made based on the control message size and/or based on the available transmission resources and/or based on the detection scheme used on the receiving end. A modulation scheme may also be selected based on such factors. CDM may be used for certain control messages. Block code encoding, such as Reed-Muller encoding may be used for certain control messages. Different transmission resources may be allocated for different control message uses. The encoding specifics may be selected to obtain a certain hamming distance and/or size of the encoded message or based on other factors. | 06-23-2011 |
