| Patent application number | Description | Published |
|---|
| 20080198828 | Multiuser detector for variable spreading factors - A multiuser detector method and receiver that detects and decodes synchronous or asynchronous CDMA subchannels having different spreading factors with reduced computational complexity. The multiuser receiver is compatible with ZF-BLE, MMSE, decorrelating detectors and the like using Cholesky decomposition to minimize numeric operations. The receiver and method arranges the columns of system transmission response matrices representing the response characteristics of individual users into a total system transmission response matrix which represents a plurality of matched-filter responses for a given block of received data. The invention when used in conjunction with Cholesky decomposition reduces the number of required mathematic operations prior to parallel matched filtering. | 08-21-2008 |
| 20080240207 | MULTI-USER DETECTION USING EQUALIZATION AND SUCCESSIVE INTERFERENCE CANCELLATION - A plurality of signals are received in a shared spectrum. Samples of the received user signals are produced as a received vector. The received vector is segmented into a plurality of segments. For each segment, successively determining symbols for each user or group of signals (the group of signals having similar received power) by determining symbols for one user/group and removing a contribution of that one user/group from the received vector. The determined symbols corresponding to each segment are assembled into a data vector. | 10-02-2008 |
| 20080267321 | EXTENDED ALGORITHM DATA ESTIMATOR - A method of data estimation for a Time Division Duplex (TDD) Code Division Multiple Access (CDMA) system or any other system using an extended algorithm (EA) in preference to a truncated algorithm (TA). The EA avoids implementation errors by choice of proper extended matrices, and accepts the use of one piece of hardware. The EA also obviates loss of multiple signals in the tail part of each data field, and avoids errors due to transformation of a Toeplitz matrix to a circulant matrix. | 10-30-2008 |
| 20080285629 | METHOD AND APPARATUS FOR TRANSFERRING SIGNALS IN A WIRELESS COMMUNICATION SYSTEM - Data is transferred in a wireless communication system, such as a wireless spread spectrum communication system. A plurality of transmitting antennas are provided. Data is encoded to produce a plurality of data streams for each of the plurality of codes. The plurality of data streams are spread with the plurality of spreading codes, and for each transmitting antenna, one of the spread data streams of each code together is combined to produce a spread data vector. Each transmitting antenna transmits its spread data vector. The transmitted spread data vectors are received by each of a plurality of receiving antennas as a received version, and the data is recovered using the received versions. | 11-20-2008 |
| 20080298523 | REDUCED COMPLEXITY SLIDING WINDOW BASED EQUALIZER - Data estimation is performed in a wireless communication system using both oversampling and multiple reception antennas. A receive vector is produced for each antenna at a sampling interval which is a multiple of the chip rate of the received signal. A channel response matrix is produced for each antenna at a preferred multiple of the sampling rate. Each receive vector is processed using a sliding window based approach, where a plurality of successive windows are processed. For each window, a combined circulant channel response matrix is produced using the channel response matrices. Using the combined circulant channel response matrix and a combined received vector comprising each received vector in a discrete Fourier transform based approach to estimate a data vector corresponding to that window; and combining the data vector estimated in each window to form a combined data vector. | 12-04-2008 |
| 20080317103 | METHOD AND APPARATUS FOR RECEIVING PLURALITY OF DATA SIGNALS - A transmitter site transmits a plurality of different data signals at a chip rate over a shared spectrum in a code division multiple access communication system. Each transmitted data signal experiences a similar channel response. A combined signal of the transmitted data signals is received. The combined signal is sampled at a multiple of the chip rate. The channel response for the combined signal is determined. A spread data vector is determined using the combined signal samples and the estimated channel response. The data of the different data signals is determined using the spread data vector. | 12-25-2008 |
| 20090046692 | METHOD FOR RECEIVING COMMUNICATION SIGNALS HAVING DIFFERING SPREADING FACTORS - A method for the simultaneous reception of data from multiple sources having different spreading factors. A plurality of transmission response matrices are generated and grouped together for equal spreading factors. A plurality of spreading factor group matrices are assembled. A base matrix is formed based upon the spreading factor group matrix having a lowest spreading factor. An additional spreading factor group matrix is selected for consideration. Column placement reference index for the base matrix is derived. A reference location for the base matrix is derived. A column set from the selected spreading factor group matrix is derived. The column set is inserted into the base matrix. A total transmission response matrix is assembled. | 02-19-2009 |
| 20090060007 | Fast joint detection base station - A code division multiple access base station receives K data signals over a shared spectrum. The base station receives and samples a combined signal having the K transmitted data signals. A combined channel response matrix is produced. A block column of a cross correlation matrix is determined using the combined channel response matrix. Each block entry of the block column is a K by K matrix. Each block entry of the block column is a K by K matrix. A fourier transform of a complex conjugate transpose of the combined channel response matrix multiplied to the combined signal samples is taken. An inverse of a fourier transform of each block entry is multiplied to a result of the fourier transform to produce a fourier transform of the data vector. An inverse fourier transform of the data vector fourier transform is taken to produce data of the K signals. | 03-05-2009 |
| 20090060098 | Algorithm for multiple-symbol differential detection - A method for differential phase evaluation of M-ary communication data is employed in which the data consists of N sequential symbols r | 03-05-2009 |
| 20090074036 | SEGMENT-WISE CHANNEL EQUALIZATION BASED DATA ESTIMATION - Data is estimated of a plurality of received spread spectrum signals by a wireless communication apparatus. The plurality of received communications are received in a shared spectrum. The received communications are sampled to produce a received vector of sequential samples. The received vector is processed to produce a plurality of segments. Each segment is processed separately to estimate data of the received communications. | 03-19-2009 |
| 20090080495 | GROUPWISE SUCCESSIVE INTERFERENCE CANCELLATION FOR BLOCK TRANSMISSION WITH RECEPTION DIVERSITY - A plurality of data signals are received over an antenna array having a plurality of antenna elements. The data signals are transmitted over a shared spectrum in a wireless communication system. A signal having each of the data signals is received over each antenna element. The plurality of data signals are grouped into a plurality of groups. The received signals of the antenna elements are matched filtered for a first group of the plurality of groups, producing a matched filtered result. Data is jointly detected of the first group using the matched filtered result. An interference correction signal is constructed using the detected data for each antenna element. The interference cancelled result is subtracted from the received signal of each antenna element, producing an interference cancelled result for each antenna element. Data is successively detected for remaining groups using the interference cancelled result for each antenna element. | 03-26-2009 |
| 20090080496 | USER EQUIPMENT FOR CONTROLLING TRANSMISSION POWER LEVELS - A user equipment (UE) with circuitry configured to determine a pathloss associated with a received signal. The circuitry is configured to receive an adjustment and adjust a value in response to the received adjustment. The circuitry is configured to determine a transmit power level based on multiplying the determined pathloss by a parameter and adding the adjusted value to a result of the multiplying, wherein the parameter is value in the range of 0 to 1. The circuitry is configured to transmit a signal at the determined transmit power level. | 03-26-2009 |
| 20090082059 | UPLINK POWER CONTROL USING RECEIVED REFERENCE SIGNAL - A method for determining uplink power level, implemented in a base station, comprises receiving a communication signal over an uplink common control channel. The interference on the uplink common control channel in response to the received communication signal is measured and a channel quality of the uplink common control channel is monitored. A quality margin for the communication signal is provided and transmitted over a downlink control channel. | 03-26-2009 |
| 20090109935 | ADAPTIVE UPLINK/DOWNLINK TIMESLOT ASSIGNMENT IN A HYBRID WIRELESS TIME DIVISION MULTIPLE ACCESS/CODE DIVISION MULTIPLE ACCESS COMMUNICATION SYSTEM - A method of adaptive uplink/downlink timeslot assignment includes determining at least one of a potentially interfering cell which potentially interferes with a particular cell. A timeslot for uplink communication is eliminated, if a first one of the potentially interfering cells uses that timeslot for downlink communications. A timeslot for downlink communication is eliminated if a dynamic interference measurement in that timeslot as measured by most users exceeds a predetermined threshold and if a dynamic interference measurement in that timeslot does not exceed the predetermined threshold for most users but exceeds the predetermined threshold for at least one user. A timeslot is assigned to an uplink communication of the particular cell using non-uplink eliminated timeslots, and a timeslot is assigned to a downlink communication of the particular cell to each user using non-downlink eliminated timeslots with respect to that user. | 04-30-2009 |
| 20090110037 | CHANNEL ESTIMATION FOR TIME DIVISION DUPLEX COMMUNICATION SYSTEMS - A plurality of communication bursts are used to communicate data in a shared spectrum in a time slot of a time division duplex communication system. Each burst has an associated midamble sequence of a set of known sequences. A wireless communication apparatus has a receiver component configured to receive the plurality of communication bursts and to define a received vector corresponding to the received bursts. A channel estimator is provided that is configured to estimate channel information of the plurality of communication bursts by constructing a block matrix having a plurality of identical right circulant matrix blocks using the known midamble sequences and the received vector. A data detector then recovers data from the received communication bursts using the estimated wireless channel information. | 04-30-2009 |
| 20090129447 | EFFICIENT JOINT DETECTION - K data signals, or bursts, are transmitted over a shared spectrum in a code division multiple access communication format. A combined signal is received and sampled over the shared spectrum, as a plurality of received vector versions. The combined signal includes the K transmitted data signals. A plurality of system matrices and an associated covariance matrix using codes and estimated impulse responses of the K data signals is produced. Each system matrix corresponds to a received vector version. The system and covariance matrices are extended and approximated as block circulant matrices. A diagonal matrix of each of the extended and approximated system and covariance matrices are determined by prime factor algorithm-fast Fourier transform (PFA-FFT) without division of the matrix. The received vector versions are extended. A product of the diagonal matrices and the extended received vector versions is taken. An inverse block discrete Fourier transform is performed by a PFA-FFT on a result of the product to produce the estimated data of the K data signals. | 05-21-2009 |
| 20090168739 | METHOD AND APPARATUS EMPLOYED IN A USER EQUIPMENT FOR INTERFERENCE SIGNAL CODE POWER AND NOISE VARIANCE ESTIMATION - Method and apparatus employed by a UE for interference signal code power noise variance estimation employing a reduced number of samples utilizing the equation | 07-02-2009 |
| 20090181715 | POWER CONTROL DURING A TRANSMISSION PAUSE - A transmitting station performs closed loop power control prior to a transmission pause. A closed loop transmission power level prior to the pause is determined. A reference signal is received and a received power level of the reference signal prior to and during the transmission pause is determined. The measured reference signal received power levels are compared to a transmit power level of the reference signals to produce a pathloss estimate of the reference signal prior to and during the transmission pause. A new transmit power level is determined by adjusting the closed loop transmission power level by a change between the prior to and during pathloss estimates. A transmission power level of the transmitting station is set to the determined new transmit power level. A communication is transmitted at the set transmission power level. | 07-16-2009 |
| 20090201905 | METHOD AND APPARATUS FOR ESTIMATING CHANNELIZATION CODES IN A WIRELESS TRANSMIT/RECEIVE UNIT - A method and apparatus for estimating channelization codes in a wireless transmit/receive unit (WTRU) using blind code detection (BCD). A WTRU receives communication bursts and detects a midamble in the received burst. A candidate code list is generated in accordance with the detected midamble. The candidate code list includes channelization codes intended for both the intended WTRU and other WTRUs. Active channelization codes among the codes in the candidate list are identified, and the identified codes are forwarded to a multi-user detector (MUD). Since the orthogonal variable spreading factor code maintains the orthogonality between codes of different SF, SFs of other WTRUs follow the SF of the intended WTRU. Moreover, since the data for other WTRUs is not used in symbol processing after MUD, the performance of MUD for the intended WTRU is preserved with the SF ambiguity of other WTRUs. | 08-13-2009 |
| 20090221239 | WEIGHTED OPEN LOOP POWER CONTROL TRANSMITTER - A weighted open loop power control transmitter for controlling transmission power levels using a spread spectrum time division duplex (TDD) technique having frames with timeslots for communication includes a demodulator configured to receive a transmitted signal from the receiver, a channel estimation device, a data estimation device, and a weighted open loop power controller. The weighted open loop power controller includes a power measurement device, a pathloss estimation device configured to receive an interpreted power level from the data estimation device and estimate the pathloss and update a long term average of the pathloss, a quality measurement device, and a transmit power calculation device for determining the transmitter's power level and to control the receiver's amplifier. | 09-03-2009 |
| 20090245220 | RANDOM ACCESS CHANNEL PREAMBLE - One out of sixteen preamble signatures is selected. A code is produced based on the selected preamble signature. The produced code is phase rotated to produce a processed preamble signature signal. The processed preamble signature signal is used in processing the CDMA RACH signal and the CDMA RACH signal is used to access a CDMA system. | 10-01-2009 |
| 20090316759 | MULTI-USER DETECTION USING EQUALIZATION AND SUCCESSIVE INTERFERENCE CANCELLATION - A method and apparatus for multi-user detection using equalization and successive interference cancellation is provided. A signal is received in a shared spectrum. Samples of the received signal are produced as a received vector. The received vector is segmented into a plurality of vector segments. For each segment, symbols for a plurality of communications are successively determined by determining symbols for a communication and removing a contribution of that communication from the vector segment. The determined symbols are assembled into a data vector for each communication. | 12-24-2009 |
| 20090323769 | SEGMENT-WISE CHANNEL EQUALIZATION BASED DATA ESTIMATION - Data is estimated of a plurality of received spread spectrum signals by a wireless communication apparatus. The plurality of received communications are received in a shared spectrum. The received communications are sampled to produce a received vector of sequential samples. The received vector is processed to produce a plurality of segments. Each segment is processed separately to estimate data of the received communications. | 12-31-2009 |
| 20100002759 | LOW BIAS ESTIMATION OF SMALL SIGNAL-TO-NOISE RATIO - A method implemented by a user equipment includes selecting a first estimate of a signal-to-noise (SNR) ratio, calculating a first amplitude and first noise variance, calculating a second amplitude and a second noise variance, calculating a second SNR, calculating a resolution value, adjusting the first SNR, and performing estimation iterations until the resolution value is equal to a predetermined value. | 01-07-2010 |
| 20100020856 | DATA DETECTION FOR CODES WITH NON-UNIFORM SPREADING FACTORS - A plurality of communication signals is received. Each communication signal has an associated code. At least two of the communication signals has a different spreading factor. The associated codes have a scrambling code period. A total system response matrix has blocks. Each block has one dimension of a length M and another dimension of a length based on in part M and the spreading factor of each communication. M is based on the scrambling code period. Data of the received plurality of communication signals is received using the constructed system response matrix. | 01-28-2010 |
| 20100067620 | REDUCED COMPLEXITY SLIDING WINDOW BASED EQUALIZER - A method and apparatus for use in data estimation in wireless communication are provided. A wireless communications signal is received and transformed to produce a received vector. The received vector is processed using a sliding window based approach that includes processing each of a plurality of windows. For each window, an approximate circulant channel response matrix is produced for use in estimating a data vector corresponding to the window. | 03-18-2010 |
| 20100074242 | SIMPLE BLOCK SPACE TIME TRANSMIT DIVERSITY USING MULTIPLE SPREADING CODES - A base station and user equipment (UE) for use in a CDMA communication system are disclosed. The base station includes a first and second antenna for transmitting first and second communication bursts. The first channelization device spreads data using a first channelization code and the second channelization device spreads the data using a second channelization code. The UE has a data detection device for receiving a signal including the first and second communication bursts. | 03-25-2010 |
| 20100103987 | METHOD AND APPARATUS FOR TRANSFERRING SIGNALS IN A WIRELESS COMMUNICATION SYSTEM - Data is transferred in a wireless communication system, such as a wireless spread spectrum communication system. A plurality of transmitting antennas are provided. Data is encoded to produce a plurality of data streams for each of the plurality of codes. The plurality of data streams are spread with the plurality of spreading codes, and for each transmitting antenna, one of the spread data streams of each code together is combined to produce a spread data vector. Each transmitting antenna transmits its spread data vector. The transmitted spread data vectors are received by each of a plurality of receiving antennas as a received version, and the data is recovered using the received versions. | 04-29-2010 |
| 20100105337 | DYNAMIC CHANNEL QUALITY MEASUREMENT PROCEDURE IMPLEMENTED IN A WIRELESS DIGITAL COMMUNICATION SYSTEM TO PRIORITIZE THE FORWARDING OF DOWNLINK DATA - A wireless digital communication system includes a base station in communication with a plurality of user equipment mobile terminals (UEs). The system prioritizes the forwarding of blocks of downlink data to designated ones of the UEs. The system employs adaptive modulation and coding (AM&C) to achieve improved radio resource utilization and provides optimum data rates for user services. Blocks of downlink (DL) data are received by the base station which requests downlink (DL) channel quality measurements only from those mobile terminals (UEs) with pending downlink transmissions. The UEs respond to the request by measuring and reporting DL channel quality to the base station, which then allocates resources such that the UEs will make best use of radio resources. The base station notifies the UEs of the physical channel allocation indicating the modulation/coding rate and allocated slots followed by transmission of blocks of downlink data which are transmitted to the UEs. | 04-29-2010 |
| 20100157948 | METHOD OF USING A: MOBILE UNIT TO DETERMINE WHETHER TO COMMENCE HANDOVER - A method of using a mobile unit in a multi-cell communication system to determine whether to commence handover of the mobile unit from a serving base station located in a first cell of the communication system to a target base station located in a second cell of the communication system. The mobile unit determines the serving base station received signal code power (RSCP | 06-24-2010 |
| 20100177743 | METHOD AND APPARATUS FOR BLIND CODE DETECTION - The present invention is a receiver which includes a blind code detection device for determining the identity of a plurality of channels over which information is to be transmitted when the identity of all channels is not known by the receiver. The blind code detection device generates a candidate channel list filled with the identify of selected channels out of the plurality of channels. A multi-user detection device, responsive to the blind code detection device, processes those channels in the candidate code list. | 07-15-2010 |
| 20100240411 | RANDOM ACCESS CHANNEL PREAMBLE - One out of sixteen preamble signatures is selected. A code is produced based on the selected preamble signature. The produced code is phase rotated to produce a processed preamble signature signal. The processed preamble signature signal is used in processing the CDMA RACH signal and the CDMA RACH signal is used to access a CDMA system. | 09-23-2010 |
| 20100254440 | METHOD AND APPARATUS FOR RECEIVING PLURALITY OF DATA SIGNALS - A transmitter site transmits a plurality of different data signals at a chip rate over a shared spectrum in a code division multiple access communication system. Each transmitted data signal experiences a similar channel response. A combined signal of the transmitted data signals is received. The combined signal is sampled at a multiple of the chip rate. The channel response for the combined signal is determined. A spread data vector is determined using the combined signal samples and the estimated channel response. The data of the different data signals is determined using the spread data vector. | 10-07-2010 |
| 20110159908 | DYNAMIC CHANNEL QUALITY MEASUREMENT PROCEDURE IMPLEMENTED IN A WIRELESS DIGITAL COMMUNICATION SYSTEM TO PRIORITIZE THE FORWARDING OF DOWNLINK DATA - A wireless digital communication system includes a base station in communication with a plurality of user equipment mobile terminals (UEs). The system prioritizes the forwarding of blocks of downlink data to designated ones of the UEs. The system employs adaptive modulation and coding (AM&C) to achieve improved radio resource utilization and provides optimum data rates for user services. Blocks of downlink (DL) data are received by the base station which requests downlink (DL) channel quality measurements only from those mobile terminals (UEs) with pending downlink transmissions. The UEs respond to the request by measuring and reporting DL channel quality to the base station, which then allocates resources such that the UEs will make best use of radio resources. The base station notifies the UEs of the physical channel allocation indicating the modulation/coding rate and allocated slots followed by transmission of blocks of downlink data which are transmitted to the UEs. | 06-30-2011 |
