Nokia Corporation

Nokia Mobile Phones Limited

Juha Heiskala

John D Terry

Tony R Reid

Kaj Tapio Jansen

Hua Zhang

Victor Stolpman

Lauri Ilari Kuru

Markku Johannes Heikkilä

Nico Van Waes

Jae H Son

Zoltan Safar

Jian Zhong Zhang

Radha Srinivasan

A semi-single frequency network (SFN) concept is presented. According to the SFN concept, the same data signal is transmitted from multiple base stations to a mobile terminal simultaneously on the same frequency band. Accordingly, the transmitted signals are combined in the radio channel and the mobile terminal experiences the transmitted signals as one signal propagated through a multipath channel. Additionally, each base station transmits a base station specific pilot signal. The mobile terminal carries out a channel estimation procedure for each received pilot signal and combines the channel estimates to obtain information how to equalize the received data signal. Then, the mobile terminal calculates equalization weights from the combined channel estimates and equalizes the received data signal.

Multipoint data transmission

A network entity in a multi-transmit antenna system, such as a transmitting or receiving entity, includes a component such as a pre-coder or a receiver, and is configured for full-spatial-rate coding data. The network entity is capable of providing a full-spatial-rate codebook having been designed by selecting an underlying partial-spatial-rate codebook designed for a system configured for partial-spatial-rate coding data. The full-spatial-rate codebook can then be designed in a manner including defining the full-spatial-rate codewords based upon partial-spatial-rate codewords of the partial-spatial rate codebook and basis vectors of a null space of the respective partial-spatial-rate codewords in a multidimensional vector space. The network entity can also be capable of selecting codewords of the codebook in accordance with a sub-space tracking method whereby the codewords of the codebook can be selected in a manner that exploits correlations therebetween.

System and method for precoding in a multiple-input multiple-output (MIMO) system

A signal vector is received over a plurality of channels. A channel matrix H is determined that represents at least one of the plurality of channels. An iterative algorithm such as Lenstra-Lenstra-Lovasz is used to determining a change of basis matrix T that when multiplied with the channel matrix H converges to a matrix H*T that is more orthogonal than the channel matrix H. In one aspect the iterative algorithm is upwardly bounded in the number of iterations (e.g., 20 or 30 iterations) that it may perform for any specific channel realization to determine the change of basis matrix T. In another aspect the algorithm is initiated with a matrix derived from a previously determined change of basis matrix. Both aspects may be combined in a single method or device, or either employed separately.

Lower complexity computation of lattice reduction

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

A method and an arrangement for compensating for amplitude imbalance of a quadrature modulator including: determining a first correlation on the basis of a first modulation signal and an output signal of the quadrature modulator; determining a second correlation on the basis of a second modulation signal and the output signal of the quadrature modulator; producing a compensation signal proportional to the amplitude imbalance on the basis of a ratio of the determined correlations and the first and second modulation signals; and processing at least one of the modulation signals of the quadrature modulator with the compensation signal; wherein determining the correlations uses unprocessed modulation signals of the quadrature modulator for determining the correlations.

Amplitude imbalance compensation of quadrature modulator

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.

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Helsinki, Finland

Juha Heiskala