A subscriber unit for use in a multiple access spread-spectrum communication system includes a spread spectrum radio interface, responsive to a rate function signal from a base station, and first and second despreaders. The base station assigns the rate function spread-spectrum message channels and the first despreader recovers and modifies an information signal one of the spread spectrum message channels. The information channel mode is then modified for processing by the second despreader, with the second despreader supporting a different information signal rate. The subscriber unit has a capability of communicating with a dynamically changing a transmission rate of an information signal which includes multiple spread spectrum message channels. The system includes a closed loop power control system for maintaining a minimum system transmit power level for a radio carrier station and the subscriber units, and system capacity management for maintaining a maximum number of active subscriber units for improved system performance.

Code division multiple access (CDMA) communication system

The object of the invention is a transmitter/receiver for transmitting and receiving of an RF signal in two frequency bands. In the solution according to the invention, a transmitter/receiver is used which is based on direct conversion and in it, when operating in both frequency bands, the mixing frequency is formed by means of the same synthesizer (340). This is implemented preferably in such a way that in the higher operating frequency, the frequency of the output signal of the synthesizer is used as such as a mixing frequency and when operating in the lower operating frequency, a mixing frequency is used which is obtained by dividing the frequency of the output signal of the synthesizer by two or a larger integer in the divider (311, 361). When the solution according to the invention is used, many synthesizers are not needed in the transmitter/receiver and no intermediate frequency components are needed.

Transmitter/receiver for transmitting and receiving of an RF signal in two frequency bands

A multiple-mode multiple band transceiver is disclosed. Some embodiments include a multiple-channel transmitter including a plurality of selectable transmit-channel components, the plurality of selectable transmit-channel components sharing at least one element coupled to a modulator, the plurality of selectable transmit channel components forming at least first and second transmit channels configured to generate radio-frequency signals using at least a first and a second multiple-access modulation technique, and a first switch configured to enable at least one of the first and second transmit channels to transmit a communication signal using at least one of the first and the second multiple-access modulation techniques.

Shared functional block multi-mode multi-band communication transceivers

The present invention relates to an arrangement for transmitting a radio-frequency signal at two different frequency bands and for receiving at two different frequency bands. The arrangement can be applied for instance to a transceiver of a radio communications system operating at two different frequency bands, or to a transceiver meant to be used in connection with two different radio communications systems. One of the ideas of the invention is that one and the same filter (72), belonging to the RF front end of the antenna circuit, is used for filtering interference from at least two signals located at different frequency bands, in which case the number of filters (72, 75) can be reduced. By means of the solution suggested in the invention, also the number of controllable switches (73) provided on the signal path of the RF front end can be minimized.

Arrangement for transmitting and receiving radio frequency signal at two frequency bands

A receiver receives signals and noise over a frequency spectrum of a desired received signal. The desired received signal is spread using code division multiple access. The received signals and noise are demodulated to produce a demodulated signal. The demodulated signal is despread using a code uncorrelated with a code associated with the desired received signal. A power level of the despread demodulated signal is measured as an estimate of the noise level of the frequency spectrum.

Automatic power control system for a code division multiple access (cdma) communications system

The dual band code division multiple access radio of the present invention operates on multiple frequencies simultaneously on either transmit or receive The transmit path operates by splitting the transmit intermediate frequency (IF) path (103) and mixing the IF to two different transmit frequencies using two frequency synthesizers (140 and 145) The receive path (104) has two RF channels (116 and 117) that are mixed with the frequencies generated by the synthesizers (140 and 145) and summed into one IF strip Thus the radio of the present invention can perform a soft hand-off between frequencies while communicating with both base stations simultaneously Additional mixing paths and synthesizers can be added if it is desired to communicate with more than two base stations simultaneously

Multiple frequency communication device

The dual band code division multiple access radio of the present invention operates on multiple frequencies simultaneously on either transmit or receive. The transmit path operates by splitting the transmit intermediate frequency (IF) path (103) and mixing the IF to two different transmit frequencies using two frequency synthesizers (140 and 145). The receive path (104) has two RF channels (116 and 117) that are mixed with the frequencies generated by the synthesizers (140 and 145) and summed into one IF strip. Thus the radio of the present invention can perform a soft hand-off between frequencies while communicating with both base stations simultaneously. Additional mixing paths and synthesizers can be added if it is desired to communicate with more than two base stations simultaneously.\!

Wheatley Charles E

Papers

Multiple frequency communication device

Multiple frequency communication device and its using method