Abstract: An offset direct conversion receiver apparatus and corresponding receiving method are provided. A received wireless signal is directly downconverted and demodulated to a baseband offset frequency that is offset from zero frequency to produce an in-phase (I) baseband offset signal centered at the baseband offset frequency and a quadrature-phase (Q) baseband offset signal centered at the baseband offset frequency. The I baseband offset signal and Q baseband offset signal are bandpass filtered to produce an I bandpass signal and a Q bandpass signal, respectively. The I bandpass signal and the Q bandpass signal are downconverted from the baseband offset frequency to zero frequency to produce an I baseband receive signal and a Q baseband receive signal. A technique and logic are also provided to select the best baseband offset frequency used in an offset direct conversion receiver.

Abstract: In one embodiment, an apparatus includes a receiver configured to receive a transmission from a wireless communication device, the transmission associated with resource units, a detector configured to generate log-likelihood ratio data from the received transmission, and a controller configured to calculate noise and interference for each of the resource units and modify the generated log-likelihood ratio data based on the calculated noise and interference.

Abstract: A method and apparatus are provided for managing radio access point (RAP) devices and enterprise controller devices in a wireless communication network. An enterprise controller device registers with a gateway device, and the enterprise controller device receives a registration request from multiple RAP devices that are serviced by the enterprise controller device. As the RAP devices register with the enterprise controller device, the enterprise controller device generates a list of the RAP devices registered with the enterprise controller. As the enterprise controller receives additional registration requests from additional RAP devices, the enterprise controller updates the list. The enterprise controller sends the list to the gateway device with which it registers so that the gateway device is aware of RAP devices serviced by the enterprise controller device. In this way, aggregated messages may be sent from the gateway device to the enterprise controller.

Abstract: Techniques are provided for a base station to transmit and receive wireless signals via a plurality of remote transceiver stations deployed in a coverage area. The remote transceiver stations are coupled to the base station in order to communicate with wireless mobile devices. A transmission time delay is determined for a message to be transmitted from corresponding remote transceiver stations to a wireless mobile device. Transmission of the message to be wirelessly transmitted from the two or more remote transceiver stations is delayed by a corresponding transmission time delay. The delayed transmissions appear as a resolvable multipath transmission to receivers in the wireless mobile user devices. Techniques are also provided for delaying the processing of uplink transmissions at the base station receiver. Delays associated with downlink or uplink transmissions may also be programmed into individual remote transceiver stations.

Abstract: Techniques are provided to performing beamforming on a wireless communication link that employs multi-carrier code division multiple access (MC-CDMA) signal formatting techniques. At a first wireless communication device, a waveform is received at each of a plurality of antennas, where the waveform comprises a multi-carrier code division multiple access ranging transmission from each of one or more of a plurality of second wireless communication devices such that MC-CDMA ranging transmissions from two or more second wireless communication devices overlap in time and frequency. All codes in a set of possible codes that may be used by the second wireless communication devices are searched to determine whether which codes in the set are present in the one or more MC-CDMA ranging transmissions contained in the received waveform.

Abstract: Techniques are provided to pre-distort a signal that is transmitted by a transmitter of a wireless communication device, e.g., a device configured for wireless radio frequency communication. The transmitter of the device inherently introduces distortion to the baseband signal to be transmitted. In at least one frame of a baseband signal to be transmitted, at least one subcarrier in a preamble of the frame is shifted in frequency such that the at least one subcarrier is offset from a normal subcarrier frequency position. The at least one frame of the baseband signal is supplied to the transmitter that is configured to produce a transmit signal for transmission. The transmit signal at an output of the transmitter is sampled or detected and inter-modulation distortion in the transmit signal is determined at one or more frequencies as a result of shifting of the frequency of the at least one subcarrier in the preamble of the at least one frame.

Abstract: A first wireless communication device recovers data from a transmission received over a wireless channel from a second wireless communication device and processes the received data with each of multiple channel variation compensations to produce corresponding processed received data subjected to respective ones of the multiple channel variation compensations. For symbols in the received data and in each of the processed received data, distances are computed to their closest symbols in a symbol constellation set used in the wireless transmission. A corresponding distance metric is computed from the distances for symbols in the received data and from the distances for symbols in each of the processed received data resulting in a distance metric for the received data, and a distance metric for each of the processed received data. Channel variation of a wireless channel between the first and second wireless communication devices is estimated based on the distance metrics.

Abstract: A hybrid time-spatial multiplexing technique is provided for beamforming broadcast messages to mobile stations that may be within a coverage region or cell of a base station. The coverage region is divided into a plurality of segments. The mobile stations are assigned to at least one of the segments based on their locations within the coverage region or other criteria. The base station computes beamforming antenna weights which are configured to produce a radiation beam pattern from a plurality of antennas of the base station to respective ones of each of the plurality of segments in the region. A broadcast message is transmitted to each segment of the region in a time-division multiplexed manner using the beamforming antenna weights associated with the radiation beam pattern for the corresponding segment.

Abstract: A method and system are provided for improving the performance of a trellis-based decoder. States with reduced uncertainty (SRUs) are defined for one or more predetermined fields in an encoded message. Metrics are set for the SRUs such that candidate paths through a trellis-based decoding process are eliminated for those states that are not SRUs.

Abstract: Techniques are provided for transmitting and receiving communications on behalf of wireless user equipment devices between a plurality of radio access point (RAP) devices and a gateway apparatus through a controller apparatus. A controller apparatus generates a plurality of first identifiers used for communications on behalf of corresponding wireless user devices between the controller apparatus and respective RAPs. Each first identifier identifies a wireless user device and a RAP to which the wireless user device is associated. The controller apparatus maps each first identifier to a corresponding one of a plurality of second identifiers for communications exchanged on behalf of the wireless user devices between the controller apparatus and a gateway apparatus in the wireless cellular communication network. The controller apparatus remaps a new first identifier to an existing second identifier when a particular wireless user device has handed over from a first RAP to a second RAP.

Abstract: Retransmitting a data sequence over a wireless network according to channel conditions proceeds by transmitting a first transmitting signal representing the data using a first set of beamforming weighting vectors generated according to a first channel condition. A request for re-transmitting the data sequence is received when the first transmitting signal suffers from unrecoverable errors. A re-transmission function is computed according to a second channel condition, and a second transmitting signal is transmitted as generated by using the re-transmission function that is created according to the second channel condition. The data sequence is demodulated and decoded using the first transmitting and the second transmitting signals.

Abstract: A system and method are provided for improving the performance of a beamforming antenna array in a wireless communications system. By observing a predetermined times of channel spatial signatures, one or more test spatial signatures are generated based on statistical analysis of the observed spatial signatures for predicting channel characteristics. A beamforming weight is derived based on the generated test spatial signatures for beamforming by an antenna subsystem of the wireless communication system.

Abstract: The present invention discloses a method for selecting a transmission scheme in a multiple-input-multiple-output (MIMO) wireless communications system. The method comprises receiving a downlink request to transmit a data stream to a wireless station, checking the availability of channel state information (CSI) associated with the wireless station, determining the validity characteristic of beamforming weighting vectors associated with the wireless station, selecting a transmission scheme from a plurality of predetermined transmission schemes based on the availability of the CSI and the validity characteristic of the beamforming weighting vectors.

Abstract: Techniques are provided herein to estimate channel information based a received burst that is comprises of consecutive transmissions. Each transmission comprises a plurality of data subcarriers and a plurality of pilot subcarriers on a radio frequency (RF) channel, wherein locations of the pilot subcarriers in the consecutive transmissions are different. Channel information at the pilot subcarriers is computed for each transmission in the burst. A time variation parameter and a frequency variation parameter of the channel for the burst are computed using the channel information at the pilot subcarriers for the transmissions in the burst. Channel information for at least one data subcarrier of a transmission in the burst is computed by interpolation and/or extrapolation of the channel information at the pilot subcarriers using the time variation parameter and the frequency variation parameter.

Abstract: Techniques are provided for wireless communication between a first wireless communication device and a second wireless communication device. At a plurality of antennas of the first wireless communication device, one or more signals transmitted by a second wireless communication device in a first frequency band are received. Beamforming weights are computed from information derived from the signals received at the plurality of antennas using one or more of a plurality of methods without feedback information from the second wireless communication device about a wireless link from the first wireless communication device to the second wireless communication device. The beamforming weights are applied to at least one transmit signal to beamform the at least one transmit signal for transmission to the second wireless communication device in a second frequency band.

Abstract: The present invention discloses a method for estimating a channel response of data subcarriers in a wireless communications network. The method comprises estimating a first plurality of channel responses of pilot subcarriers carrying pilot signals at the time instance using pilot signals, generating a pseudo time instance for pilot subcarriers according to a predetermined rule, approximating a second plurality of channel responses at the pseudo time instance using the first plurality of channel responses, computing a rate of change in the channel response using the first and second plurality of channel responses, calculating a third plurality of channel responses of pilot subcarriers carrying data at the time instance using the first plurality of channel responses and the rate of change in the channel response, estimating the channel response of the data subcarriers from the first and third plurality of channel responses using a predetermined conventional two-dimensional channel estimation algorithm.

Abstract: An adaptive transmission selection technique is provided. A retransmission scheme is selected for a multiple-input-multiple-output wireless system. A plurality of communication techniques is provided for when a first device needs to retransmit a signal to a second device. The first device determines when the original signal, transmitted to the second device using beamforming techniques, needs to be retransmitted to the second device. If a retransmission is needed, the first device determines channel conditions with respect to the second device. The first device selects a retransmission scheme from a plurality of transmission schemes based on the channel conditions for retransmitting the signal. A first retransmission technique is selected when the channel conditions are static. A second retransmission technique is selected when the channel conditions are relatively slowly changing, and a third retransmission technique is selected when the channel conditions are relatively quickly changing.

Abstract: A system and method are provided for improving the performance of a beamforming antenna array in a wireless communications system. A predetermined number of spatial signatures are observed for a communications channel between a base station and a mobile terminal during a predetermined time period. One or more test spatial signatures are generated based on statistical analysis of the observed predetermined number of spatial signatures. A beamforming weight is derived based on the generated test spatial signatures for beamforming by an antenna subsystem of the base station.

Abstract: Techniques are provided to enable wireless communication between first and second wireless communication devices each having a plurality of antennas, where the second device sends the transmissions via less than all of its plurality of antennas. Each transmission may comprise a plurality of time-frequency instances. At the first communication device, data is derived representing parameters of a communication channel between the plurality of antennas of the first device and all of the plurality of antennas of the second device from the transmissions received at the plurality of antennas of the first device. Beamforming weights for transmitting one or more signal streams via the plurality of antennas of the first device to the plurality of antennas of the second device are computed based on the data representing parameters of the communication channel between the plurality of antennas of the first device and the plurality of antennas of the second device.

Abstract: A method for partitioning a plurality of antennas in a wireless communication system, in which the antennas are grouped into a first set of partitions and a second set of partitions. One or more signal transmission schemes are performed with the antennas grouped into the first set of partitions for a first time period, and then with the antennas grouped into the second set of partitions for a second time period.