A method and apparatus for dynamically modifying filter characteristics of a delta-sigma modulator in order to perform signal equalization of a signal in the delta signal modulator. The system is used for wide bandwidth radio system designed to adapt to various global radio standards and, more particularly, to a cellular radio architecture that employs a combination of a single circulator, programmable band-pass sampling radio frequency (RF) front-end and optimized digital baseband that is capable of supporting all current cellular wireless access protocol frequency bands.

A method and apparatus for dynamically modifying filter characteristics of a Delta-Sigma modulator. The system is used for wide bandwidth radio system designed to adapt to various global radio standards and, more particularly, to a cellular radio architecture that employs a combination of a single circulator, programmable band-pass sampling radio frequency (RF) front-end and optimized digital baseband that is capable of supporting all current cellular wireless access protocol frequency bands.

Method for propagation channel estimation in an NM Multiple-Input-Multiple-Output (MIMO) communication system comprising a transmitter (202) comprising N transmit antennas and a receiver (204) comprising M receive antennas and a MIMO equalizer (206) comprising multiple taps, where N>1 and M>1. The method includes producing (s402) a single tap equalizer (Q) based on a multi-tap equalizer (Q). The method also includes producing (s404) an inverse effective-channel estimate (Q.sub.e) based on Q, The method also includes inverting (s406) Q.sub.e to produce an effective-channel estimate (H.sub.e), The method also includes producing (s408) H.sub.a based on H.sub.ewherein H.sub.a can be used to determine one or more performance metrics.

Devices, systems and method for enabling radio communications between a plurality of users are disclosed herein. In an embodiment, a mobile tactical device includes a radio connection interface, a first frequency converter, a frequency filter, and a second frequency converter. The radio connection interface is configured to receive a first radio communication having a mobile frequency from a mobile radio. The first frequency converter is configured to convert the mobile frequency to an intermediate frequency. The frequency filter is configured to pass or reject the intermediate frequency. The second frequency converter is configured to convert the intermediate frequency to an assigned transmission frequency for transmission of the first communication when the intermediate frequency passes the at least one frequency filter.

According to some embodiments, an apparatus for generating multiple variable frequency and phase locked clock signals comprises complex tuners, digital up-samplers, image isolation filters, quadrature modulators, a combiner, a DAC, a local oscillator, and an analog filter. The complex tuners tune multiple digital baseband signals. The up-samplers interpolate the complex tuned digital signals such that one of the up-sampled images of each of the complex tuned digital signals corresponds to a desired frequency. The image isolation filters isolate images corresponding to the desired frequencies. The quadrature modulators convert the isolated images of the complex tuned digital signals into real digital signals. The combiner combines the real digital signals into a combined real digital signal. The DAC, driven by the local oscillator, converts the combined real digital signal into an analog clock signal. The analog filter then filters the analog clock signal to select images located at the desired frequencies.

A base station apparatus of mobile communication system is provided, including an antenna system including first antenna for transceiving signals for a first path among MIMO paths, and a second antenna for transceiving signals for a second path among the MIMO paths, a first duplexer including transmission filter for processing the transmitted signal of first path and reception filter for processing the received signal of second path, a second duplexer including reception filter for processing the received signal of first path and transmission filter for processing the transmitted signal of second path, and a path change unit for providing the transmitted signal provided from the first duplexer to the first antenna and the received signal provided from the first antenna to the second duplexer and to provide the transmitted signal from the second duplexer to the second antenna and the received signal from the second antenna to the first duplexer.

A base station apparatus of mobile communication system is provided, including an antenna system including first antenna for transceiving signals for a first path among MIMO paths, and a second antenna for transceiving signals for a second path among the MIMO paths, a first duplexer including transmission filter for processing the transmitted signal of first path and reception filter for processing the received signal of second path, a second duplexer including reception filter for processing the received signal of first path and transmission filter for processing the transmitted signal of second path, and a path change unit for providing the transmitted signal provided from the first duplexer to the first antenna and the received signal provided from the first antenna to the second duplexer and to provide the transmitted signal from the second duplexer to the second antenna and the received signal from the second antenna to the first duplexer.

Devices, systems and method for enabling radio communications between a plurality of users are disclosed herein. In an embodiment, a mobile tactical device includes a radio connection interface, at least one frequency filter and a controller. The radio connection interface is configured to receive communications from a mobile radio in a plurality of mobile frequencies. The frequency converter is configured to convert the plurality of mobile frequencies selected at the mobile radio into a plurality of transmission frequencies. The controller stores an assigned mobile frequency and an assigned transmission frequency for each of multiple talk groups. The controller is configured to set the frequency converter to convert communications from the mobile radio to the assigned transmission frequency for a specific talk group of the multiple talk groups upon determining that the assigned mobile frequency for the specific talk group has been selected at the mobile radio.

A signal processing device includes a filter, configured to receive first data representing a signal for wireless transmission, modify the first data in a filter operation, and output second data as the modified first data; a peak detector, configured to detect third data representing a peak of the signal, wherein the third data are a subset of the first data; a signal canceller, configured to receive the third data and to generate fourth data representing a cancellation signal corresponding to the peak of the signal; and a peak modifier, configured to receive the second data and the fourth data, and to generate fifth data using the second data and the fourth data, wherein the fifth data represent the signal with a modified peak.

A base station apparatus of mobile communication system is provided, including an antenna system including first antenna for transceiving signals for a first path among MIMO paths, and a second antenna for transceiving signals for a second path among the MIMO paths, a first duplexer including transmission filter for processing the transmitted signal of first path and reception filter for processing the received signal of second path, a second duplexer including reception filter for processing the received signal of first path and transmission filter for processing the transmitted signal of second path, and a path change unit for providing the transmitted signal provided from the first duplexer to the first antenna and the received signal provided from the first antenna to the second duplexer and to provide the transmitted signal from the second duplexer to the second antenna and the received signal from the second antenna to the first duplexer.