Transmission power control for use in a transmitting apparatus in a CDMA communication system

• US 6,628,929 B1
• Filed: 06/18/1999
• Issued: 09/30/2003
• Est. Priority Date: 06/18/1998
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Nomura, Tominari
• Primary Examiner(s): Maung, Nay
• Assistant Examiner(s): SOBUTKA, PHILIP
• Application Number:
  US09/335,889
• Time in Patent Office: 1,565 Days
• Field of Search: 370/311, 370/320, 370/335, 370/342, 370/441, 455/69, 455/522, 455/126, 375/295, 375/296, 375/146
• US Class Current: 455/126
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

In a transmission power control unit for use in a transmitting apparatus, power control amount correctors carry out, on the basis of detected signals, correction of power control amounts on transmission amplitude data to produce corrected data. A power control correction code generator generates a power control correction code. Spreading sections carry out spread processings on the corrected data using replaced spreading codes into which respective parts of spreading codes are replaced with the power control correction code. A multiplexer multiplexes spread data into a multiplexed amplitude datum. A D/A converter converts the multiplexed amplitude datum into an analog signal. A radio section carries out modulation, frequency conversion, and power amplification on the analog signal to produce a transmission signal. A distributor extracts a part from the transmission signal as an extracted signal. A frequency converter converts the extracted signal into a frequency-converted signal. A despreading section carries out a despread operation on the frequency-converted signal to detect transmission power for the respective channels. A timing controller generates a clock signal for synchronizing the despreading section and the spreading sections.

Claims

1. A method of controlling transmission power in a transmission amplitude datum, said method comprising the steps of:

spreading the transmission amplitude datum into a spread datum;

converting the spread datum into a transmission signal;

extracting a part of the transmission signal as an extracted signal; and

adjusting the transmission amplitude datum on the basis of the extracted signal.

3. A method as claimed in claim 1, wherein the step of spreading is carried out using a replaced spreading code into which a part of a spreading code is replaced with a power control correction code, the step of despreading being carried out using the power control correction code.

4. A method as claimed in claim 3, wherein the power control correction code has orthogonality and a code length which is extremely shorter than that of the spreading code.

2. A method of controlling transmission power in a transmission amplitude datum, said method comprising the steps of:

spreading the transmission amplitude datum into a spread datum;

converting the spread datum into a transmission signal;

extracting a part of the transmission signal as an extracted signal;

despreading the extracted signal to obtain transmission power in the transmission amplitude datum; and

adjusting the transmission amplitude datum on the basis of the obtained transmission power.

5. A method of controlling transmission power in a transmitting apparatus for transmitting first through N-th transmission amplitude data for first through N-th channels with the first through the N-th transmission amplitude data multiplexed, where N represents a positive integer which is not less than two, said method comprising the steps of:

spreading the first through the N-th transmission amplitude data into first through N-th spread data, respectively;

multiplexing the first through the N-th spread data into a multiplexed amplitude datum;

converting the multiplexed amplitude datum into a transmission signal;

extracting a part of the transmission signal as an extracted signal;

despreading the extracted signal to produce first through N-th detected signals indicative of transmission power for the first through the N-th channels, respectively; and

adjusting the first through the N-th transmission amplitude data on the basis of the first through the N-th detected signals, respectively.

6. A method as claimed in claim 5, wherein the step of spreading is carried out using first through N-th replaced spreading codes into which respective parts of first through N-th spreading codes assigned with the first through the N-th channels are replaced with a power control correction code, the step of despreading being carried out using the power control correction code.

7. A method as claimed in claim 6, wherein the power control correction code has orthogonality and a code length which is extremely shorter than that of each of the first through the N-th spreading codes.

8. A method as claimed in claim 7, wherein replacement timings to the power control correction code are different from each channel.

9. A transmission power control unit for use in a transmitting apparatus for transmitting first through N-th power-controlled transmission amplitude data for first through N-th channels with the first through the N-th power-controlled transmission amplitude data multiplexed, where N represents a positive integer which is not less than two, said transmission power control unit comprising:

first through N-th power control amount correctors supplied with the first through the N-th power-controlled transmission amplitude data, respectively, said first through said N-th power control amount correctors carrying out, on the basis of first through N-th detected signals, correction of first through N-th power control amounts on the first through the N-th power-controlled transmission amplitude data to produce first through N-th corrected data, respectively;

a power control correction code generator for generating a power control correction code for detection of transmission power;

first through N-th spreading sections connected to said first through said N-th power control amount correctors, respectively, and to said power control correction code generator in common, said first through said N-th spreading sections carrying out first through N-th spread processings on the first through the N-th corrected data using first through N-th replaced spreading codes into which respective parts of first through N-th spreading codes assigned with the first through the N-th channels are replaced with the power control correction code, respectively, said first through said N-th spreading section producing first through N-th spread data;

a multiplexer, connected to said first through said N-th spreading sections, for multiplexing the first through the N-th spread data by summing up the first through the N-th spread data, said multiplexer producing a multiplexed amplitude datum;

a digital-to-analog converter, connected to said multiplexer, for converting the multiplexed amplitude datum into an analog signal having an analog value corresponding to the multiplexed amplitude datum;

a radio section, connected to said digital-to-analog converter, for carrying out modulation, frequency conversion, and power amplification on the analog signal to produce a transmission signal;

extracting means, connected to said radio section, for extracting a part from the transmission signal as an extracted signal;

a frequency converter, connected to said extracting means, for converting the extracted signal into a frequency-converted signal having a frequency which enables the frequency-converted signal to digitally process;

a despreading section connected to said frequency converter, said power control correction code generator, and said first through said N-th power control amount correctors, said despreading section carrying out a despread processing on the frequency-converted signal to detect first through N-th momentary transmission power for the first through the N-th channels, said despreading section supplying said first through said N-th power control amount correctors with the first through the N-th detected signals indicative of the first and the N-th momentary transmission power, respectively; and

a timing controller, connected to said despreading section and said first through said N-th spreading sections, for generating a clock signal for synchronizing said despreading section and said first through said N-th spreading sections, said timing controller supplying said despreading section with the clock signal, said timing controller supplying said first through said N-th spreading sections with first through N-th timing signals, respectively.

10. A transmission power control unit as claimed in claim 9, wherein the power control correction code has orthogonality and has a code length which is extremely shorter than that of each of the first through the N-th spreading codes.

11. A transmission power control unit as claimed in claim 9, wherein an n-th power control amount corrector, where n represents each of 1 through N, comprises:

an n-th analog-to-digital converter, supplied with an n-th detected signal, for converting the n-th detected signal into an n-th detected datum;

an n-th buffer, connected to said n-th analog-to-digital converter and supplied with the n-th power-controlled transmission amplitude datum, for successively buffering the n-th detected datum and the n-th power-controlled transmission amplitude datum into n-th stored detected data and n-th stored power-controlled transmission amplitude data; and

an n-th processing section, connected to said n-th buffer, for processing the n-th stored detected data and the n-th stored power-controlled transmission amplitude data to produce an n-th processed datum as the n-th corrected datum.

12. A transmission power control unit as claimed in claim 9, wherein an n-th spreading section, where n represents each of 1 through N, comprises:

an n-th spreading code generator for generating an n-th spreading code for an n-th channel;

an n-th switch, connected to said n-th spreading code generator, said power control correction code generator, and said timing controller, for selecting, in response to an n-th timing signal, one of the n-th spreading code and the power control correction code as an n-th selected code, said n-th switch producing the n-th selected code as an n-th replaced spreading code; and

an n-th multiplier, connected to said n-th switch and an n-th power control amount corrector, for multiplying an n-th corrected datum by the n-th replaced spreading code to produce an n-th multiplied datum as an n-th spread datum.

13. A transmission power control unit as claimed in claim 12, wherein the power control correction code has orthogonality and has a code length which is extremely shorter than that of the n-th spreading code.

14. A transmission power control unit as claimed in claim 9, wherein said radio section comprises:

a modulator, connected to said digital-to-analog converter, for modulating a carrier having an intermediate frequency by the analog signal to produce a modulated signal;

a second frequency converter, connected to said modulator, for converts the modulated signal having the intermediate frequency into a second frequency-converted signal having a high frequency; and

a power amplifier, connected to said second frequency converter, for power amplifying the second frequency-converted signal into a power-amplified signal, said power amplifier producing the power-amplified signal as the transmission signal.

15. A transmission power control unit as claimed in claim 9, wherein said despreading section comprises:

a multiplier, connected to said frequency converter and said power control correction code generator, for multiplying the frequency-converted signal by the power control correction code to produce a multiplied signal; and

a selector, connected to said multiplier and said timing controller, for selecting the multiplied signal in response to the clock signal to supplying said first through said N-th power control amount correctors with the first through the N-th detected signals, respectively.

16. A transmission power control unit as claimed in claim 9, wherein said timing controller comprises:

a clock oscillator for oscillating the clock signal comprising a plurality of clock pulses, said clock oscillator supplying said despreading section with the clock signal; and

a selector, connecting said clock oscillator, for selecting ones of the clock pulses in the clock signal to supply said first through said N-th spreading sections with the first through the N-th timing signals, respectively.

17. A transmission power control unit as claimed in claim 9, wherein said transmitting apparatus is a radio base station apparatus for use in a code division multiple access (CDMA) communication system.

18. A transmission power control unit as claimed in claim 9, wherein said transmitting apparatus is a mobile station apparatus for use in a code division multiple access (CDMA) communication system.

19. A method of controlling transmission power in a radio base station apparatus for use in a code division multiple access (CDMA) communication system, said method comprising the steps of:

replacing a part of a spreading code assigned with each channel with a power control correction code having orthogonality to produce a replaced spreading code, the power control correction code having a code length which is extremely shorter than that of the spreading code;

spreading a spectrum of a transmission datum using the replaced spreading code to produce a transmission signal;

despreading the transmission signal using the power control correction code to measure transmission power in the transmission datum each channel; and

carrying out, on the basis of measured transmission power, transmission power control for the transmission datum each channel.