Pre-phase error correction

• US 9,100,250 B2
• Filed: 07/25/2014
• Issued: 08/04/2015
• Est. Priority Date: 03/28/2000
• Status: Expired due to Fees

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Kaewell, John D. Jr.
• Primary Examiner(s): Tran, Khanh C
• Application Number:
  US14/341,181
• Publication Number:
  US 20140334528A1
• Time in Patent Office: 375 Days
• Field of Search: 375/130, 375/140, 375/146, 375295-296, 375/271, 375/279, 375/284, 375/308, 455/63.1, 455/67.13, 455/114.2, 455/115.1
• US Class Current: 1/1
• CPC Class Codes: H04B 1/62 for providing a predistortion of the signal in the transmitter and corresponding correction in the receiver, e.g. for improving the signal/noise ratio
• CPC Class Codes: H04B 1/69 Spread spectrum techniques
• CPC Class Codes: H04B 1/7097 Interference-related aspects
• CPC Class Codes: H04B 1/711 the interference being multi-path interference
• CPC Class Codes: H04B 2001/70724 featuring pilot assisted reception
• CPC Class Codes: H04B 2201/696 relating to Dowlink
• CPC Class Codes: H04B 2201/709709 Methods of preventing interference
• CPC Class Codes: H04L 2027/0022 using the carrier of the associated receiver of a transceiver
• CPC Class Codes: H04L 27/20 Modulator circuits; Transmitter circuits

Abstract

A CDMA communication system includes a signal processor which encodes voice and nonvoice signals into data at various rates, e.g. data rates of 8 kbps, 16 kbps, 32 kbps, or 64 kbps as I and Q signals. The signal processor selects a specific data rate depending upon the type of signal, or in response to a set data rate. When the signal is received and demodulated, the baseband signal is at the chip level. Both the I and Q components of the signal are despread using the conjugate of the pn sequence used during spreading, returning the signal to the symbol level. Carrier offset correction is performed at the symbol level. A lower overall processing speed is therefore required.

Claims

1. A method implemented in a base station, the method comprising:

adjusting, by the base station, a phase of a plurality of spread data signals in response to a correction signal, the correction signal including weights to adjust the phase of the data signals and wherein the correction signal was received from a mobile device;

transmitting, by the base station, the plurality of phase adjusted data signals to the mobile station; and

transmitting, by the base station, a spread pilot signal.

2. The method of claim 1 wherein each of the plurality of data signals is transmitted over an in-phase and a quadrature carrier of a radio frequency signal.

3. The method of claim 1 wherein the pilot signal is a quadrature phase shift keying (QPSK) signal.

4. The method of claim 1 wherein each of the data signals is a quadrature phase shift keying (QPSK) signal.

5. The method of claim 1 wherein the spread data signals only include data.