Nokia Corporation

Qualcomm Incorporated

Nokia Mobile Phones Limited

Nokia Networks Oy

John D Terry

Victor Stolpman

Sridhar Rajagopal

Matthew Brendan Shoemake

Pirjo Pasanen

Juha Heiskala

Olav Tirkkonnen

Olav Tirkkonen

Steven Daniel Gray

Dumitru Mihai Ionescu

Jari Jokela

Mihai Ionescu

Radha Srinivasan

The present invention provides a method and apparatus for detecting interference in a wireless communications system. The invention compares the receiver FFT output of a received signal against known sequences such as the packet synchronization sequence, frame synchronization sequence, and channel estimation sequence. By comparing the reference signal to the known sequences, the invention estimates the instantaneous signal to noise ratio (SNR) for each tone of a wireless transmission. To improve the SNR estimate, the invention computes a weighted average across multiple OFDM symbols. The invention looks for significant increases (spikes) in the SNR as a way of distinguishing interfering signals from noise. The invention can store separate SNR estimates for each transmitter in a wireless network. One embodiment of the invention uses Viterbi branch metrics in conjunction with the estimated SNR to determine the presence of an interfering signal. If interference is detected the invention feeds the inverse of the SNR estimate into the Viterbi decoder or declares and erasure for that symbol.

Detection and mitigation of interference and jammers in an OFDM system

Apparatus, and an associated method, for allocating data to communication channels of a multiple-input communication system and to select power levels at which the data is caused to be communicated upon the communication channels. Data allocation is made responsive to communication quality indications that identify communication conditions on the different ones of the channels. Data allocation and power level allocation is made to achieve best a selected performance parameter.

Apparatus, and associated method, for allocating data for communication upon communication channels in a multiple input communication system

Apparatus, and an associated method, for facilitating communication of communication data upon a communication channel susceptible to distortion. Both diversity techniques and spatial multiplexing techniques are utilized to compensate for the distortion introduced upon the data during its communication. Separate parts of the communication data are mapped pursuant to separate mapping schemes. The mapping schemes are selected to exhibit different properties. When the communication data is communicated upon the communication channel and delivered to a receiving station, a decoder decodes the data to recover the informational content of the data.

Apparatus, and associated method, for communicating communication data in a multiple-input, multiple-output communication system

A method and apparatus for encoding data for wireless transmission. The invention includes multi-level coding in which data is partitioned between two encoders, one for encoding Most Significant Bits (MSBs) and the other for encoding Least Significant Bits (LSBs). By partition bits separately for the MSBs and LSBs, the complexity of the decoder may be reduced. The MSBs and LSBs are interleaved such that each MSB is a function of just one LSB, simplifying branch metric selection during Viterbi decoding. This also allows parallel de-interleaving by the receiver, which reduces the interleaving latency of the receiver. A block interleaver jointly optimizes the symbol hamming distance of the symbols and the bit hamming distance of each constituent encoder for the MSBs and LSBs.

Method and apparatus for encoding interleaving and mapping data to facilitate GBPS data rates in wireless systems

In a MIMO delay spread (OFDM) system or a MIMO single carrier (non-OFDM) system wherein a transmitter transmits signals to a receiver through multipath fading channels, an equivalent frequency-domain MIMO multipath channel matrix is used to estimate the maximum mutual information regarding the relationship between transmitted signals and received signals. It is possible to compute the upper bound of the maximum mutual information at least based on the total energy of all resolvable paths in the fading channels. The upper bound or the changes in the upper bound can be used to adjust the transmission parameters used in data transmission. The transmission parameters include the modulation order in the modulation process, the code rate and the puncturing rate.

Method and device for transmission parameter selection in mobile communications

Apparatus, and an associated method, for facilitating optimization of the communication capacity of a communication system. A selector is coupled to receive channel state information associated with the channel conditions upon subcarriers defined pursuant to an OFDM (orthogonal frequency division multiplexing) the selector operates to select communication allocation of the data to be communicated on the different ones of the subcarriers. Selection is made pursuant to a selected optimization scheme. And, bit and power profiles are formed that are utilized to control the modulation scheme by which data is modulated upon the different subcarriers. As channel conditions change, the communication allocations are adaptively altered.

Apparatus, and associated method, for facilitating communication allocation in a radio communication system

A method and apparatus for aggregating packets in a wireless communication system. The data to be transmitted is selected and packetized and formed into frames for transmission. Rather than send each frame individually, frames are grouped and transmitted with grouping indicia informing the recipients how to acknowledge successful receipt of the transmitted data. ACKs are sent at a predetermined time, or all together, divided by subcarrier in the case of an OFDMA network.

Method and apparatus for packet aggregation in a wireless communication network

Apparatus, and an associated method, for facilitating communication of data upon a communication channel which exhibits fading. Orthogonal transmit diversity techniques and trellis-coded modulation techniques are utilized to form a signal permitting the communication of data at high data rates while maintaining spectral efficiency, good error rate performance, without excessive computational complexity. The apparatus and associated method is advantageously implemented in a WLAN (Wireless Local Area Network) constructed pursuant to the IEEE 802.11 standard.

Apparatus, and associated method, for forming a modulated signal utilizing OTD and TCM techniques

An inventive method provides optimum topology for a multi-antenna system dedicated to higher throughput/capacity by bundling the Point Coordination Function (PCF) operation in infrastructure mode of the current and/or enhanced IEEE MAC with PHY specifications that employ some form of coherent weighting based on CSI at the transmitter in conjunction with the corresponding optimum receiver detection based on CSI. Specifically, CSI is measured from a control message, so data messages and control messages are separated. In the contention period of IEEE 802.11, the RTS/CTS exchange is used for CSI and the data message is sent following the CTS message. In the contention free period, a poll by the PC is separated from a data frame, which gives the polled station the first opportunity to send a data message. This change in topology results in various changes to the frame exchange format in the CFP for various scenarios of data and control messages to be exchanged.

System topologies for optimum capacity transmission over wireless local area networks

Apparatus, and associated method, for increasing the diversity levels of data communicated upon a channel susceptible to fading. Trellis-coded modulation is performed upon data to be communicated to form trellis-coded modulated and rotated symbols. Coordinate interleaving is performed by a coordinate interleaver upon selected ones of the modulated and rotated symbols. The coordinate interleaving is performed according to a selected coordinate interleaving scheme responsive to indications of channel conditions upon the communication channel. When delivered to a receiving station, a coordinate deinterleaver deinterleaves the interleaved symbols according to a coordinate deinterleaving scheme that corresponds to the coordinate interleaving scheme.

Coordinate interleaving, and deinterleaving, apparatus, and associated method, for a communication system

Apparatus, and an associated method, by which to form biorthogonal codes utilized in a multi-dimensional modulation scheme. In one implementation, biorthogonal coding is provided in a cellular communication system in a manner that minimizes correlation of pairs of coordinates utilized in the communication system. Data that is to be communicated by a sending station is first modulated by a binary phase shift keying modulation. These first-modulated values are used by a mapper that maps the values to selected dimension values. And, the selected dimension values into which the first-modulated values are mapped are used to select biorthogonal code values.

Apparatus, and associated method, for coding and decoding multi-dimensional biorthogonal codes

Apparatus, and an associated method, for encoding and decoding data in a communication system. A hybrid dimensional Spherical Space-Time Code (SSTC) scheme is provided. Data to be transmitted upon a communication channel is encoded, and when received at a receiving station, the encoded sequence is decoded.

Hybrid dimensional, spherical space-time coding and decoding apparatus, and associated method, for a communication system

An M-ary signal constellation within an N-dimensional space is defined, preferably such that each of the M symbols reside upon the surface of an N-dimensional sphere and such that a minimum distance between symbols is maximized. N orthogonal functions are used as the bases for representing the N-dimensional symbols for transmission. Orthogonal functions exhibiting orthogonality in frequency, time and/or space are also described for this purpose. Furthermore, conventional QAM symbol encoding may be used to represent the N-dimensional symbols, thereby facilitating the use of conventional modulation techniques. In this manner, higher dimensional modulation schemes may be realized.

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Garland, TX, United States of America

John D Terry