US 6,324,208 B1 · Apparatus and method of controlling transmitting power in a subscriber of a wireless telecommunications system

Abstract

A wireless telecommunications systems (1) includes a central terminal (10) for transmitting and receiving radio frequency signals to and from a subscriber terminal (20). A downlink communication path is established from a transmitter (200) of the central terminal (10) to a receiver (202) of the subscriber terminal (20). A downlink signal (212) is transmitter from the transmitter (200) to the receiver (202) during setup and operation of the wireless telecommunications system (1). The receiver (202) of the subscriber terminal (20) compares a code and phase of a master code sequence in the downlink signal (212) to a code and phase of a slave code sequence of the receiver (202). The receiver (202) adjusts the phase of the slave code sequence until a match is obtained with the master code sequence. The downlink signal (212) includes an overhead channel (224) having a power control signal (236), a code synchronization signal (234), and a frame alignment signal (232). The power control signal (236) is capable of adjusting a transmitting power of a transmitter (204) in the subscriber terminal (20). The code synchronization signal (234) is capable of adjusting a phase of a transmitter (204) in the subscriber terminal (20). A receiver (206) in the central terminal (10) monitors an uplink signal (214) transmitted by the transmitter (204) in the subscriber terminal and provides changes to the code synchronization signal (234) such that the transmitter (204) is synchronized to the receiver (206). The receiver (202) monitors the downlink signal (212) to identify the frame alignment signal (232) and establishes the downlink communication path when two successive frame alignment signals (232) are identified. The wireless telecommunications system (1) operates in one of three operating modes. In an acquisition mode during establishment of the downlink communication path, the downlink signal (212) is transmitted at a high power level and a low transmit rate with the receiver (202) operating at the low transmit rate. In a standby mode after establishment of the downlink communication path, the downlink signal (212) is transmitted at a low power level and a low transmit rate with the receiver (202) operating at the low transmit rate. In a traffic mode upon a request for wireless communication transmission, the downlink signal (212) is transmitted at a high power level and a high transmit rate with the receiver (202) adjusting to operate at the high transmit rate. Upon completion of the wireless communication transmission, the wireless telecommunications system (1) returns to the standby mode and the receiver (202) adjusts to operate at the low transmit rate.

Claims35

Dependent claims

A subscriber terminal for communicating with a central terminal located at a fixed distance from the subscriber terminal, the subscriber terminal comprising:

a receiver operable to establish a downlink communication path from the central terminal to the subscriber terminal;
a transmitter for transmitting an uplink signal to the central terminal;
a spreader operable to receive an information signal, the spreader further operable to combine the information signal with a code sequence signal to generate a spread signal for transmission;
the receiver being operable to receive a code synchronization signal from the central terminal using a wireless link, the code synchronization signal having a value determined as a result of comparing within the central terminal the phase of the uplink signal with the phase of a receiver in the central terminal;
and
a code generator coupled to the spreader, the code generator operable to generate the code sequence signal in response to the code synchronization signal, the code synchronization signal specifying a phase adjustment to the code sequence signal.

3 more elements

A method for wireless communication between a subscriber terminal and a central terminal located at a fixed distance from the subscriber terminal, the method comprising the following steps performed at the subscriber terminal:

establishing a downlink communication path from the central terminal to the subscriber terminal;
transmitting an uplink signal from a transmitter in the subscriber terminal;
receiving an information signal associated with a user channel of the subscriber terminal;
receiving a code synchronization signal from the central terminal using a wireless link, the code synchronization signal having a value determined as a result of comparing within the central terminal the phase of the uplink signal with the phase of a receiver in the central terminal;
generating a code sequence signal in response to the code synchronization signal, the code synchronization signal specifying a phase adjustment to the code sequence signal;
and
combining the information signal with the code sequence signal to generate a spread signal for transmission.

4 more elements

Dependencies are inferred from the claim text.

Apparatus and method of controlling transmitting power in a subscriber of a wireless telecommunications system

Life of this patent

Apparatus and method of controlling transmitting power in a subscriber of a wireless telecommunications system

Life of this patent

Abstract

Claims35