Abstract: In an OFDM communication system, wherein a frequency bandwidth is divided into multiple Physical Resource Units (PRUs), a Frequency Partitioning Configuration Module (FPCM) is provided that configures a physical layer for use in multiple coverage areas. The FPCM divides the PRUs into a first group, for frequency selective allocations, and a second group, for frequency diverse allocations. The FPCM subdivides each of the two groups into multiple sets of PRUs, maps the sets of PRUs from the first group to consecutive PRUs allocated for contiguous segment allocation (CS-PRUs), and maps the sets of PRUs from the second group to consecutive PRUs allocated for distributed segment allocation (DS-PRUs). The FPCM permutes the DS-PRUs and allocates the CS-PRUs and the permuted DS-PRUs to at least one frequency partition.

Abstract: During operation, the choice of the initial ranging code (sometimes referred to as a ranging preamble code, or a random-access preamble) at the mobile station is associated with a PMI feedback to be signaled to the base station during the initial ranging. More particularly, during initial system access a ranging code is transmitted by the mobile station to the base station. The mobile station chooses one of the available ranging codes based on the channel conditions and associates the ranging code with channel feedback information. The ranging code is then transmitted to the base station, and provides the base station with the channel feedback information.

Abstract: In an OFDM communication system, wherein a frequency bandwidth is divided into multiple Physical Resource Units (PRUs), a Frequency Partitioning Configuration Module (FPCM) is provided that configures a physical layer for use in multiple coverage areas. The FPCM divides the PRUs into a first group, for frequency selective allocations, and a second group, for frequency diverse allocations. The FPCM subdivides each of the two groups into multiple sets of PRUs, maps the sets of PRUs from the first group to consecutive PRUs allocated for contiguous segment allocation (CS-PRUs), and maps the sets of PRUs from the second group to consecutive PRUs allocated for distributed segment allocation (DS-PRUs). The FPCM permutes the DS-PRUs and allocates the CS-PRUs and the permuted DS-PRUs to at least one frequency partition.

Abstract: Channel information feedback takes place by calculating channel information to feed back to the base station. The channel quality information is spread by a remote unit with spreading codes from mutually unbiased bases and transmitted to the base station. The advantages of spreading the feedback channel are that multiple mobiles can send their feedback on the same time-frequency resources making the feedback very efficient and also improving feedback performance through orthogonal spreading which gives a spreading gain above noise and interference. Using the spreading codes from mutually unbiased bases can reduce interference across sectors.

Abstract: A generalized form of cyclic shift diversity is described for use in an OFDM system with multiple transmit antennas. Multiple cyclic shifts are performed for each transmit antenna and the shifted signals are scaled and summed to form a time-domain data stream for each transmit antenna. A cyclic extension is added to each data stream prior to transmission.

Abstract: A generalized form of cyclic shift diversity is described for use in an OFDM system with multiple transmit antennas. Multiple cyclic shifts are performed for each transmit antenna and the shifted signals are scaled and summed to form a time-domain data stream for each transmit antenna. A cyclic extension is added to each data stream prior to transmission.

Abstract: Constrained feedback tap weights of a decision feedback equalizer are determined by iteratively solving a non-linear equation for a constraint multiplier. The non-linear equation is based on a 2-norm of feedback tap weights constrained by an explicit constraint constant.

Abstract: Constrained tap weights of a decision feedback equalizer are determined according to the channel impulse response of a channel and a constraint function. The constraint function is differentiable and is an approximation of a non-differentiable tap weight constraint function. The tap weight constraint function may have a constraint value M that is a function of a mean squared error of the estimated mean squared error at the output of the decision feedback equalizer.

Abstract: An electronic system with power approximation for circuit savings. Power approximation is provided by means for generating an absolute value of a real part of a signal, means for generating an absolute value of an imaginary part of the signal, means for generating a sum of the absolute values, and means for performing an averaging function on the sum such that a result of the averaging function provides an approximate power which indicates an actual power of the signal. The approximate power enables a determination of actual signal-to-noise ratio in the electronic system and a determination of a variety of other signal-to-noise determinations without the use of multipliers.

Abstract: An adaptive equalizer for a demodulator includes a filter that generates a filter output signal in response to an information signal according to a transfer function for the filter. The adaptive equalizer includes means for adjusting the transfer function in response to an indication of error in the filter output signal, and means for switching among a set of differing determinations of the indication of error. Switching among the differing determinations may be based upon a variety of indications of the progress of adaptation in the equalizer.

Abstract: Constrained tap weights of a decision feedback equalizer are determined according to the channel impulse response of a channel and a constraint function. The constraint function is differentiable and comprises an approximation of a non-differentiable tap weight constraint function. The tap weight constraint function may have a constraint value M that is a function of a mean squared error of the estimated means squared error at the output of the decision feedback equalizer.

Abstract: An adaptive equalizer for a demodulator includes a filter that generates a filter output signal in response to an information signal according to a transfer function for the filter. The adaptive equalizer includes means for adjusting the transfer function in response to an indication of error in the filter output signal, and means for switching among a set of differing determinations of the indication of error. Switching among the differing determinations may be based upon a variety of indications of the progress of adaptation in the equalizer.

Abstract: An electronic system with power approximation for circuit savings. Power approximation is provided by means for generating an absolute value of a real part of a signal, means for generating an absolute value of an imaginary part of the signal, means for generating a sum of the absolute values, and means for performing an averaging function on the sum such that a result of the averaging function provides an approximate power which indicates an actual power of the signal. The approximate power enables a determination of actual signal-to-noise ratio in the electronic system and a determination of a variety of other signal-to-noise determinations without the use of multipliers.

Abstract: A demodulator with a filter having a reduced number of filter taps without a sacrifice in filter accuracy. The demodulator includes elements that generate a data stream that carries a component of an input signal in response to a data stream that carries samples of the input signal. The demodulator also includes elements that generate a sample clock for sampling the input signal such that the sample clock is preselected to cause the data stream that carries the component to carry alternating samples that are substantially equal to zero. The filter in the demodulator has a set of filter taps which are arranged to tap only the samples in the data stream that carries the component that are not substantially equal to zero.