Abstract: Methods are described of processing a signal transmitted over a channel in a wireless communication system. A method includes estimating at intervals at least one parameter of a time varying communication environment of said system. At least one processor-related signal processing criterion can be monitored for implementing a signal processing activity. Based on said at least one parameter and said at least one processor-related criterion, a signal processing function can be selected from a plurality of signal processing functions implementable by a processor. Each signal processing function includes a plurality of code blocks having a sequence of instructions for execution on a processor platform, the processor platform including a set of configurable operators having a plurality of predetermined configurations, each sequence of instructions including at least one configuration instruction, which selects one of the plurality of predefined configurations for executing that code block.

Abstract: An apparatus and method for implementing an equalizer which (1) combines the benefits of a decision feedback equalizer (DFE) with a maximum-a-posterori (MAP) equalizer (or a maximum likelihood sequence estimator, MLSE) (2) performs equalization in a time-forward or time-reversed manner based on the channel being minimum-phase or maximum-phase to provide an equalization device with significantly lower complexity than a full-state MAP device, but which still provides improved performance over a conventional DFE. The equalizer architecture includes two DFE-like structures, followed by a MAP equalizer. The first DFE forms tentative symbol decisions. The second DFE is used thereafter to truncate the channel response to a desired memory of L1 symbols, which is less than the total delay spread of L symbols of the channel. The MAP equalizer operates over a channel with memory of L1 symbols (where L1<=L), and therefore the overall complexity of the equalizer is significantly reduced.

Abstract: This invention describes an apparatus and method to improve the performance of a decision feedback equalizer (DFE) for time-varying multi-path channels. For minimum-phase channels, the equalization is performed in a time-forward manner. For maximum-phase channels, the equalization is performed in a time-reversed manner. More specifically, for maximum-phase channels, the filter coefficients are computed based on the channel estimates reversed in time, and the filtering and equalization operations are performed with the received block of symbols in a time-reversed order. In the context of this invention, the term “minimum-phase channel” implies that the energy of the leading part of the channel profile is greater than the energy of the trailing part. The term “maximum-phase channel” implies that the energy of the leading part of the channel profile is less than the energy of the trailing part.

Abstract: According to an embodiment of the invention, a method and system is disclosed for determining log-likelihood ratios for a coded set of individual bits (40) of a quadrature amplitude modulation (QAM) codeword. In the method at most two constant values (33,35) may be determined to perform a set of predetermined functions, the output of each of function is based on the constant values and at least one received component corresponding to the codeword, to determine log-likelihood ratios (37) for each individual bit of the set of individual bits of the codeword. The QAM codeword may correspond to at least a portion of a signal of a wireless device, such as a mobile third-generation device operating according to a Wideband Code-Division Multiple Access (WCDMA) standard.

Abstract: A base station with a defined geographic coverage area in a wireless communication system includes a base receiver, a base transmitter, and a base antenna array. The base antenna array has a base station beamformer arranged to produce (a) a broad antenna beam so that the base station can receive random access signals from subscriber stations at different locations within the coverage area and transmit beacon or acknowledgment signals to the subscriber stations at the different locations, and (b) a narrow antenna beam directed to an acknowledged subscriber station for receiving or transmitting data or traffic signals from or to the subscriber station. A subscriber station includes a subscriber receiver, a subscriber transmitter and a subscriber antenna. The subscriber transmitter is arranged to transmit signals to a system base station on one or more of a number of carriers having a defined frequency spacing within a given spectrum allotment.