Abstract: A receiver in an OFDM based communication system is adapted to perform channel estimation using a received reference signal transmitted from at least one antenna The reference signal is substantially located into at least two OFDM symbols of a transmission time interval comprising of more than two OFDM symbols. A power level of said reference signal is divided into said non-consecutive OFDM symbols in said transmission time interval and adapted to use the reference signal located in a first OFDM symbol in succeeding transmission time intervals in addition to the reference symbols in a current transmission time interval and a preceding transmission time interval.

Abstract: A device for communicating digital data over power lines includes a power line interface for transmitting data over at least one band of frequencies. An orthogonal frequency division multiplexing (OFDM) modulation unit generates OFDM symbols using a set of tones for the frequency band. A preamble generation unit generates preamble sequences for the frequency band by using the set of tones used by the OFDM modulation unit. The tones used by the preamble generation unit have a constant magnitude, and a set of phases obtained by quantizing to a small alphabet the phase of a set of tones obtained by taking an IFFT of a portion of a preamble used by a non-interoperable powerline access device. The device may transmit on two or more bands using a sampling frequency clock, wherein a lower band clock frequency is equal to or an integer divisor of a higher band clock frequency.

Abstract: Embodiments of the invention provide a receiver in an OFDM based communication system adapted to perform channel estimation using a received reference signal transmitted from at least one antenna, said reference signal being substantially located into two OFDM symbols of a transmission time interval comprising of more than two OFDM symbols. A method of generating pilot structure, the pilot structure provides information to an apparatus for channel estimation in the OFDM system with a transmission time interval of seven OFDM symbols. The pilot structure comprising pilot signals from at least one transmitting antenna located in various OFDM symbols of the transmission time interval.

Abstract: A Hybrid Automatic Retransmission Request (H-ARQ) technique is provided for Multi-Input Multi-Output (MIMO) systems. The technique changes the basis (V) upon retransmission, which helps reduce the error probability upon retransmission. This basis hopping technique provides for improved performance gain without significant increase in design complexity. In one embodiment, communication device (100) includes a receiver section (114) for receiving an acknowledgment (ACK) or a non-acknowledgment (NACK) signal in response to information transmitted by the transmitter section of the communication device. If a NACK is received, a new basis is selected from a set of basis stored in a basis set unit (110). The new basis that is selected is then used by a linear transformation unit (106) in the retransmission of the information.

Abstract: Embodiments of the invention provide embodiments of the invention provide and method, network entity and user equipment for slow uplink power control of user equipment in a wireless communication system by responding to a long term control metric that is derived from an uplink channel metric over a plurality of transmission instances and a set of performance criteria. A method for slow uplink power control in accordance with and embodiment of the invention measures at least one uplink channel metric for user equipment and then determines an appropriate transmit power for the user equipment by using a control metric derived from the uplink channel metric corresponding to a plurality of transmission instances for the user equipment.

Abstract: Embodiments of the invention provide method and apparatus for generating a structure in an orthogonal frequency division multiplexing OFDM communication system having a transmitter with one or more transmitting antennas. The method includes composing a frame with a time domain and a frequency domain. The frame has a transmission time interval in the time domain and occupies a bandwidth in the frequency domain. The transmission time interval has multiple orthogonal frequency division multiplexing symbols. A pilot signal is located from a transmitting antenna into two non-consecutive orthogonal frequency division multiplexing symbols of the frame.

Abstract: System and method for simplifying preamble detection and reducing power consumption in receivers. A preferred embodiment comprises a preamble made up of two sequences, a first sequence that is specified in the time domain and a second sequence that is specified in the frequency domain. The first sequence which comprises multiple copies of a time domain code sequence can allow easy detection of the preamble while the second sequence comprises multiple copies of a frequency domain code sequence and allows easy determination of the frequency response of the communications channel. A hierarchical sequence can be used to allow multi-stage correlation. This can result in a less complex correlator, hence lower power consumption. Piconets can use different code sequences to allow rapid determination of the source of a transmission without requiring the receiver to decode the entire transmission.

Abstract: A receiver (MST) for use in a modulated communications system wherein data is communicated in a time-slotted format. The receiver comprises circuitry (22) for providing samples of a group of data from the time-slotted format and circuitry (46, 42) for determining a first set of channel estimates in response to a first set of the samples. The receiver also comprises circuitry (30) for first predicting decisions for data in the group of data in response to the first set of channel estimates and circuitry (46, 42) for determining a second set of channel estimates in response to the predicted decisions. Lastly, the circuitry for predicting is further for second predicting decisions for data in the group of data in response to the second set of channel estimates.

Abstract: Apparatus and method for accessing a wireless telecommunications network by transmitting a random access signal. The random access signal includes a cyclic prefix signal and a guard interval. The cyclic prefix signal and the guard interval are adapted to optimize random access channel coverage in a telecommunications cell. The disclosed method for transmitting a random access signal includes transmitting a cyclic prefix signal. The duration of the cyclic prefix signal is approximately the sum of a maximum round trip delay duration of the telecommunications cell and a maximum delay spread duration. The method further includes providing a guard interval. The guard interval duration being approximately the duration of the maximum round trip delay of the telecommunications cell.

Abstract: A method described evaluates the pilot-to-data power ratio based on the values of the demodulated data at the output of a receiver such as a conventional maximal ratio combiner or an equalizer receiver. Since the data are not scaled to their particular decision grid, their distribution and statistics deviate from the ones defined by the known decision grid. Measuring these deviations of the statistics, the pilot-to-data power ratio and the appropriate demodulated data scaling can be accurately determined. Subsequent data processing may then commence.

Abstract: System and method for interference cancellation in a digital wireless communications system. A preferred embodiment comprises sampling a received signal wherein the received signal is real-valued, rotating the sampled received signal by a specified amount, extracting in-phase and quadrature phase streams from the rotated, sampled received signal, applying an interference suppression filter and combining the filtered streams. The output of the combining operation can be de-correlated (by whitening) if there is excessive correlation.

Abstract: An efficient bit interleaving scheme for a multi-band OFDM ultra-wideband (UWB) system. The encoded bits of the multi-band OFDM system are interleaved within each OFDM symbol and across OFDM symbols. The bit interleaving scheme minimizes performance degradation due to groups of contiguous OFDM tones experiencing a poor SNR caused by the frequency selective channel, exploits the frequency diversity across sub-bands, randomizes the effect of co-channel interference from simultaneously operating un-coordinated piconets, and randomizes the impact of generic narrow-band interferers present within the UWB spectrum.

Abstract: A wireless communication system (10). The system comprises a user station (12). The user station comprises despreading circuitry (22) for receiving and despreading a plurality of slots received from at least a first transmit antenna (A121) and a second transmit antenna (A122) at a transmitting station (14). Each of the plurality of slots comprises a first channel (DPCH) comprising a first set of pilot symbols and a second channel (PCCPCH) comprising a second set of pilot symbols. The user station further comprises circuitry (50) for measuring a first channel measurement (?1,n) for each given slot in the plurality of slots from the first transmit antenna and in response to the first set of pilot symbols in the given slot. The user station further comprises circuitry (50) for measuring a second channel measurement (a2,n) for each given slot in the plurality of slots from the second transmit antenna and in response to the first set of pilot symbols in the given slot.

Abstract: Embodiments of the invention provide methods for maximizing the bandwidth utilization in the uplink of a communication system supporting time division multiplexing between unicast and multicast/broadcast communication modes during transmission time intervals in the downlink of a communication system. This is accomplished by multiplexing at least unicast control signaling for UL scheduling assignments in TTIs supporting the multicast/broadcast communication mode. Moreover, multiplexing of unicast control signaling can also be accomplished by splitting a symbol of the multicast/broadcast TTI into two shorter symbols with the first of these two shorter symbols carrying at least unicast control signaling and the second of these shorter symbols carrying multicast/broadcast signaling.

Abstract: The present invention provides an image-rejecting channel estimator for use with an orthogonal frequency division multiplex (OFDM) receiver employing scattered pilot channel estimates. In one embodiment, the image-rejecting channel estimator includes an estimation interpolator configured to provide channel estimates through time interpolation and frequency interpolation employing the scattered pilot channel estimates. The image-rejecting channel estimator also includes an image-rejection formatter coupled to the estimation interpolator and configured to provide image-rejection filtering to suppress an image in an output spectrum of the channel estimates from at least one of the time interpolation and frequency interpolation.

Abstract: Spread spectrum rake receiver estimates number of paths within a chip interval and assigns corresponding fingers. Cross-correlation matrix eigenvalues or direct BER estimates for differing numbers of fingers determine whether one or two fingers assigned to the group of paths within a chip.

Abstract: Embodiments of the invention provide method and structure for boosting pilot signal power relative to data signal power. The velocity of user equipment is obtained. The velocity measurement is used in determining the transmission power of the pilot signal and applying the increase to a plurality of pilots and decreasing the data signal power by a proportional amount.

Abstract: Closed loop multiple-antenna wireless communications system with antenna weights determined by maximizing a composite channel signal-to-interference-plus-noise ratio minimum. Multiplexed symbol streams over subsets of antennas enhance throughput.

Abstract: Embodiments of the invention provide embodiments of the invention provide and method, network entity and user equipment for slow uplink power control of user equipment in a wireless communication system by responding to a long term control metric that is derived from an uplink channel metric over a plurality of transmission instances and a set of performance criteria. A method for slow uplink power control in accordance with and embodiment of the invention measures at least one uplink channel metric for user equipment and then determines an appropriate transmit power for the user equipment by using a control metric derived from the uplink channel metric corresponding to a plurality of transmission instances for the user equipment.

Abstract: Embodiments of the invention provide method and apparatus for generating a structure in an orthogonal frequency division multiplexing communication system having a transmitter with a least one transmitting antenna, said method comprising; composing a frame with a time domain and a frequency domain, wherein the frame has a transmission time interval in the time domain and locating a pilot signal, having pilot power level, from a first at least one antenna into two orthogonal frequency division multiplexing symbols of said frame.