Abstract: Capacity of radio links in an in-building cellular communication system is currently limited by bandwidth available for a communications link between a terminal and a single base station. The present invention mitigates this limitation by permitting the terminal to establish a number of communications links with a number of base stations. Content data is distributed in parallel over the number of communications links.

Abstract: Equalisation of a communication channel is achieved through use of a Wiener filter frequency response mechanism that operates to transform at least a portion of a data stream generated from a plurality of space time coded (STC) symbol streams received from a plurality of transmit antenna elements into a packet spectrum. A training sequence for a channel through which the symbol streams have been sent is also transformed to a channel impulse response spectrum in order to assess the channel impulse response for the channel. The packet spectrum is equalised with the channel impulse response spectrum to produce an equalised packet spectrum in the transform domain. This is then converted into a time domain equalised data stream for recovery of originally transmitted information.

Abstract: Multiple Steiner codes are transmitted as bursts from multiple base stations (182, 184, 186) having one or more transmit elements (174, 176, 178, 180), with successive bursts providing an extended training sequence for use in channel estimation at an addressed unit (172), such as a mobile handset. Accurate channel estimation is possible through the use of Wiener frequency domain MMSE deconvolution (518) combined with frequency domain spatial decoupling matrices, with quasi-orthogonal pseudo-noise sequences (502, 504, 520, 522) allocated to base stations and their antenna elements. The use of Steiner codes to supplement Wiener frequency domain MMSE deconvolution and frequency domain spatial decoupling results in the possibility of allocating only a single training sequence to each base station provided that the training sequence is of sufficient length to encompass all multiple time-translated channel impulse responses (H).

Abstract: The use of cyclic prefixes with OFDM transmissions is known. Typically the prefix length is chosen to be at least as long as the duration of significant multipath in the transmission channel. However, OFDM has disadvantages in terms of DSP load and transmitter power amplifier specifications. The use of a cyclic prefix with periodic CDMA codes has been found to yield equivalent performance in terms of orthogonality in a dispersive channel and yet overcomes the disadvantages of cyclicly prefixed OFDM transmissions. Examples are given of Walsh Hadamard binary periodic codes.

Abstract: The disclosure relates to wireless communications such as cdma systems where variable orthogonal spreading factors are employed. Code words are selected from a representation known as the orthogonal variable spreading factor (OVSF) tree, which allows code words of different length to be mixed yet remain orthogonal. The present invention provides a system whereby a subset of codes are employed whereby the bit rate can be reduced. This is of particular advantage under poor propagation conditions. Mutual interference between users is reduced.

Abstract: The present invention provides a method whereby an adaptive equaliser is applied to the terminal (mobile) receivers in a cellular radio CDMA system whose purpose is to minimise the mutual interference between users sharing the same radio channel. The application relevant to third generation cellular systems which consist of UTRA (or WBCDMA) in Europe and CDMA2000 in the USA (or future merged standards variants of these systems), and has a special application to the time domain duplex (TDD) mode of these systems. An algorithm is provided whereby the equaliser is adapted to conform to some recognised optimality criterion which is known to lead to a minimum mutual interference situation. One method is the constrained minimum output finite impulse response (FIR) digital filter power condition, but the technique is not limited to this criterion. The method reduces the computation load of a digital filter by selecting a sparse subset of delay line taps which are actively weighted and used as a filter.