Patent application number | Description | Published |
20090274232 | REVERSE LINK POWER CONTROL IN AN ORTHOGONAL SYSTEM - A closed-loop reverse-link power control algorithm for a frequency hopping orthogonal frequency division multiple access (FH-OFDMA) system is described. The power control algorithm adjusts the user's transmit power based on effective carrier-to-interference (C/I) and Received-Power-Over-Thermal (RpOT) measurements. The algorithm is inherently stable and is effective for FH-OFDMA systems with retransmissions. | 11-05-2009 |
20100029265 | SYSTEMS AND METHODS THAT UTILIZE A CAPACITY-BASED SIGNAL-TO-NOISE RATIO TO PREDICT AND IMPROVE MOBILE COMMUNICATION - Techniques for utilizing a capacity-based effective signal-to-noise ratio (SNR) to improve wireless communication are described herein. In an embodiment, a mobile terminal can determine the effective SNR from a forward link channel using pilot/data symbols. The mobile terminal can convey the effective SNR to a base station. In order to minimize transmission overhead, the mobile terminal can quantize the effective SNR prior to transmitting it to the base station. In another embodiment, the base station can determine the effective SNR from a reverse link. The base station can utilize the effective SNR to facilitate scheduling transmissions from the mobile terminal, transmitting power control commands to the mobile terminal, and determining a supporting data rate for the mobile terminal, for example. Suitable SNRs include constrained, unconstrained, average, and/or approximated effective SNRs. In addition, various filters, such as an averaging filter, can be utilized to further process the effective SNR. | 02-04-2010 |
20100238896 | ON-HAND REVERSE-LINK PILOT TRANSMISSION - Pilots are transmitted on demand on a reverse link and used for channel estimation and data transmission on a forward link. A base station selects at least one terminal for on-demand pilot transmission on the reverse link. Each selected terminal is a candidate for receiving data transmission on the forward link. The base station assigns each selected terminal with a time-frequency allocation, which may be for a wideband pilot, a narrowband pilot, or some other type of pilot. The base station receives and processes on-demand pilot transmission from each selected terminal and derives a channel estimate for the terminal based on the received pilot transmission. The base station may schedule terminals for data transmission on the forward link based on the channel estimates for all selected terminals. The base station may also process data (e.g., perform beamforming or eigensteering) for transmission to each scheduled terminal based on its channel estimate. | 09-23-2010 |
20100238902 | Channel Structures for a Quasi-Orthogonal Multiple-Access Communication System - A channel structure has at least two channel sets. Each channel set contains multiple channels and is associated with a specific mapping of the channels to the system resources available for data transmission. Each channel set may be defined based on a channel tree having a hierarchical structure. To achieve intra-cell interference diversity, the channel-to-resource mapping for each channel set is pseudo-random with respect to the mapping for each remaining channel set. In each scheduling interval, terminals are scheduled for transmission on the forward and/or reverse link. The scheduled terminals are assigned channels from the channel sets. Multiple terminals may use the same system resources and their overlapping transmissions may be separated in the spatial domain. For example, beamforming may be performed to send multiple overlapping transmissions on the forward link, and receiver spatial processing may be performed to separate out multiple overlapping transmissions received on the reverse link. | 09-23-2010 |
20100254354 | Softer and Soft Handoff in an Orthogonal Frequency Division Wireless Communication System - Transmission patterns for pilot symbols transmitted from a mobile station or base station are provided. The patterns may be selected according to a location of the mobile station with respect to one or more antennas are provided. In some aspects, the pattern may be selected based upon the distance between the mobile station and the one or more antennas. In other aspect, the pattern may be based upon whether the mobile station is in handoff. | 10-07-2010 |
20110059699 | RATE SELECTION FOR A QUASI-ORTHOGONAL COMMUNICATION SYSTEM - A selected rate is received for an apparatus based on a hypothesized signal-to-noise-and-interference ratio (SINR) for the apparatus, and characterized statistics of noise and interference observed at a receiver for the apparatus. Data are processed in accordance with the rate selected for the apparatus. | 03-10-2011 |
20110296279 | ROBUST ERASURE DETECTION AND ERASURE-RATE-BASED CLOSED LOOP POWER CONTROL - Techniques for performing erasure detection and power control for a transmission without error detection coding are described. For erasure detection, a transmitter transmits codewords via a wireless channel. A receiver computes a metric for each received codeword, compares the computed metric against an erasure threshold, and declares the received codeword to be “erased” or “non-erased”. The receiver dynamically adjusts the erasure threshold based on received known codewords to achieve a target level of performance. For power control, an inner loop adjusts the transmit power to maintain a received signal quality (SNR) at a target SNR. An outer loop adjusts the target SNR based on the status of received codewords (erased or non-erased) to achieve a target erasure rate. A third loop adjusts the erasure threshold based on the status of received known codewords (“good”, “bad”, or erased) to achieve a target conditional error rate. | 12-01-2011 |
20120270582 | INTERFERENCE CONTROL IN A WIRELESS COMMUNICATION SYSTEM - For interference control, a sector m estimates interference observed from terminals in neighbor sectors and obtains an interference estimate. Sector m may generate an over-the-air (OTA) other-sector interference (OSI) report and/or an inter-sector (IS) OSI report based on the interference estimate. Sector m may broadcast the OTA OSI report to the terminals in the neighbor sectors. These terminals may adjust their transmit powers based on the OTA OSI report. Sector m may send the IS OSI report to the neighbor sectors, receive IS OSI reports from the neighbor sectors, and regulate data transmissions for terminals in sector m based on the received IS OSI reports. Sector m may control admission of terminals to sector m, de-assign admitted terminals, schedule terminals in sector m in a manner to reduce interference to the neighbor sectors, and/or assign the terminals in sector m with traffic channels that cause less interference to the neighbor sectors. | 10-25-2012 |