Spread spectrum communication system and transmission power control method therefor

• US 20080192706A1
• Filed: 04/14/2008
• Published: 08/14/2008
• Est. Priority Date: 01/20/1995
• Status: Active Grant

• Current Assignee: Nobukazu Doi, Takashi Yano
• Original Assignee: Nobukazu Doi, Takashi Yano
• Inventors: Doi, Nobukazu, Yano, Takashi
• Granted Patent: US 8,711,761 B2
• Time in Patent Office: Days
• US Class Current: 370/335
• CPC Class Codes: H04B 1/707 using direct sequence modulation
• CPC Class Codes: H04B 1/7097 Interference-related aspects
• CPC Class Codes: H04W 52/08 Closed loop power control
• CPC Class Codes: H04W 52/24 using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/58 Format of the TPC bits

Abstract

In a spread spectrum communication system, one (W.sub.n) of a series of orthogonal codes for spectrum spreading is assigned to signal-to-noise ratio measurement in a terminal. On the basis of a noise signal detected by de-spreading a signal received from an antenna with the above described orthogonal code (W.sub.n) and a pilot signal, each terminal derives a signal-to-noise ratio. Each terminal transmits the signal-to-noise ratio to the base station as a power control signal. On the basis of signal-to-noise information received from each terminal as the power control signal, the base station controls signal transmission power for each terminal.

Claims

1. A base station for communicating with a mobile station in a wireless communication system, comprising:

a transmitting circuit for transmitting a first signal over a first channel, and a second signal over a second channel which is different from said first channel;

a reception circuit for receiving a third signal transmitted from said mobile station; and

a transmission controller for controlling transmission of a signal,

wherein said third signal received from said mobile station is generated by the mobile station according to a measurement of said first signal received at said mobile station, and

wherein said transmission controller controls transmission of said second signal to said mobile station based on said third signal.

2. A mobile station for communicating with a base station in a wireless communication system, comprising:

a reception unit for receiving, from said base station, a first signal via a first channel and a second signal via a second channel which is different from said first channel, and measuring said first signal;

a signal generator for generating a third signal according to first signal; and

a transmission unit for transmitting said third signal to said base station,

wherein said third signal is used for controlling transmission of said second signal.