Abstract: A wireless communication system (100), method, and base station (112) are provided for optimizing performance of a base station receiver (120). The method includes selecting an interpolation matrix (216) specially tailored for particular channel characteristics from a pre-defined set of interpolation matrices (218), and using the selected interpolation matrix in the channel estimation, and applying the derived channel estimates for the data subcarriers to an equalizer (118) as a set of weights. The interpolation matrix (216) is selected by using the matrix corresponding to a received channel profile information, or by monitoring a performance metric (212) while using each interpolation matrix of a pre-defined set of matrices in the channel estimation and applying the derived channel estimates for the data subcarriers as a set of weights to the receiver equalizer (118) and selecting the matrix resulting in best performance.

Abstract: A method and apparatus are provided for digitizing a wide frequency bandwidth signal (105). The digitizing is accomplished by separating the wide frequency bandwidth signal (105) into a plurality of narrow frequency bandwidth signals with a plurality of filters (110). Subsequently, a converter (120) generates digitized samples of the narrow frequency bandwidth signals. Finally, a composite digitized signal (160) is generated by a combiner (150) from the digitized samples which substantially represents the wide frequency bandwidth signal (105).

Abstract: An equalization system for equalizing a corrupted signal is disclosed. The equalization system includes a complex matched filter (400) and a maximum likelihood sequence estimator (MLSE) (405) for removing the effects of phase shift, amplitude variations, intersymbol interference, etc. resulting from multi-pathing and noise contributed by the receiver front end. The system estimates a correlation signal C(t) (505) and synchronizes C(t) 505 to maximize its energy as seen on the taps of the complex matched filter (400). Taps having amplitude coefficients below a predetermined threshold are set to zero to produce a modified CIR estimate. The modified CIR estimate which has had the effects of noise virtually eliminated, is then used to construct the complex matched filter (400) and is also used as input to the MLSE (405) to produce a better equalized data signal.

Abstract: A method and appartus for diversity reception in a communication system wherein at least a dual branch receiver is provided with a stored replica of expected reference information that is correlated with the received time-dispersed signals to obtain an estimate of the transmission channel's impulse response as seen by each branch, and determine, among other things, phase error between the branch local oscillators and the time-dispersed signals. Matched filters are constructed which then coherently align the time-dispersed signals from each branch with that branch's local oscillator, also constituting the first part of the equalization. The diversity processing stage may perform bit by bit selection on the re-aligned signals, maximal ratio combining of the re-aligned signals, or equal gain combining of the re-aligned signals, following each by a sequence estimation which uses similarly selected or combined channel distortion compensation parameters to complete the equalization process on the new signal.

Abstract: An antenna switching system for handling high traffic sectors in a cellular radiotelephone system. The system switches the cell's base station transmitters to sectors that have more mobile traffic than they can handle. The additional transmitters increase the number of frequencies in the overloaded sector, thereby allowing a greater amount of mobile traffic to use the cell.

Abstract: A power amplifier is provided for amplifying a radio frequency signal such as in a burst modulation manner for use in GSM cellular radio. The amplifier has means, such as a ROM (16), for producing a predetermined sequence of values in response to a control pulse. Means (21) are provided for converting each value into a power control signal, and control means (9) are provided for controlling the amplifier output power in accordance with said power control signal. In this manner, the power/time characteristic can be made to take the form of a raised cosine. The invention also provides power selection means for selecting a nominal output level from a plurality of discrete levels and for selecting power sub-levels offset from said selected level. An indication is recorded as to which sub-level best represents the nominal power level.

Abstract: An antenna switching system for handling high traffic sectors in a cellular radiotelephone system. The system switches the cell's base station transmitter to sectors that have more mobile traffic than they can handle. The additional transmitters increase the number of frequencies in the overloaded sector, thereby allowing a greater amount of mobile traffic to use the cell.