SYSTEM FOR USING RAPID ACQUISITION SPREADING CODES FOR SPREAD-SPECTRUM COMMUNICATIONS

• US 20100157950A1
• Filed: 03/02/2010
• Published: 06/24/2010
• Est. Priority Date: 06/30/1995
• Status: Abandoned Application

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Lomp, Gary R., Ozluturk, Fatih M.
• Application Number:
  US12/715,709
• Publication Number:
  US 20100157950A1
• Time in Patent Office: Days
• US Class Current: 370/335
• CPC Class Codes: G06F 13/374 using a self-select method with individual priority code comparator
• CPC Class Codes: H03H 17/0226 comprising look-up tables
• CPC Class Codes: H03H 17/06 Non-recursive filters
• CPC Class Codes: H03H 21/0018 Matched filters
• CPC Class Codes: H03H 2218/06 Multiple-input, multiple-output [MIMO]; Multiple-input, single-output [MISO]
• CPC Class Codes: H04B 1/7075 with code phase acquisition
• CPC Class Codes: H04B 1/70752 Partial correlation
• CPC Class Codes: H04B 1/70753 Partial phase search
• CPC Class Codes: H04B 1/70755 Setting of lock conditions, e.g. threshold
• CPC Class Codes: H04B 1/70758 Multimode search, i.e. using multiple search strategies
• CPC Class Codes: H04B 1/708 Parallel implementation
• CPC Class Codes: H04B 1/7085 using a code tracking loop, e.g. a delay-locked loop
• CPC Class Codes: H04B 1/7093 Matched filter type
• CPC Class Codes: H04B 1/7115 Constructive combining of multi-path signals, i.e. RAKE receivers
• CPC Class Codes: H04B 1/712 Weighting of fingers for combining, e.g. amplitude control or phase rotation using an inner loop
• CPC Class Codes: H04B 2201/70701 featuring pilot assisted reception
• CPC Class Codes: H04B 2201/70702 Intercell-related aspects
• CPC Class Codes: H04B 2201/70703 using multiple or variable rates
• CPC Class Codes: H04B 2201/70707 Efficiency-related aspects
• CPC Class Codes: H04B 2201/7071 with dynamic control of receiver resources
• CPC Class Codes: H04B 7/2628 : using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA] H04B7/2618 takes precedence
• CPC Class Codes: H04B 7/2637 : for logical channel control
• CPC Class Codes: H04B 7/264 : for data rate control
• CPC Class Codes: H04J 13/004 : Orthogonal
• CPC Class Codes: H04J 13/10 : Code generation
• CPC Class Codes: H04J 13/107 : by concatenation
• CPC Class Codes: H04L 1/004 : by using forward error control H04L1/0618 takes precedence; coding, decoding or code conversion, for error detection or correction H03M13/00
• CPC Class Codes: H04L 2027/003 : at baseband only
• CPC Class Codes: H04L 2027/0053 : Closed loops
• CPC Class Codes: H04L 25/0212 : of impulse response
• CPC Class Codes: H04L 27/206 : using a pair of orthogonal carriers, e.g. quadrature carriers
• CPC Class Codes: H04L 27/2332 : using a non-coherent carrier
• CPC Class Codes: H04L 5/1446 : of transmission speed
• CPC Class Codes: H04W 52/08 : Closed loop power control
• CPC Class Codes: H04W 52/146 : Uplink power control
• CPC Class Codes: H04W 52/24 : using SIR [Signal to Interference Ratio] or other wireless path parameters
• CPC Class Codes: H04W 52/26 : using transmission rate or quality of service QoS [Quality of Service]
• CPC Class Codes: H04W 52/322 : Power control of broadcast channels
• CPC Class Codes: H04W 52/325 : Power control of control or pilot channels
• CPC Class Codes: H04W 52/343 : taking into account loading or congestion level
• CPC Class Codes: H04W 52/36 : with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 52/367 : Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/44 : in connection with interruption of transmission
• CPC Class Codes: H04W 52/50 : at the moment of starting communication in a multiple access environment
• CPC Class Codes: H04W 52/52 : using AGC [Automatic Gain Control] circuits or amplifiers
• CPC Class Codes: H04W 52/54 : Signalisation aspects of the TPC commands, e.g. frame structure
• CPC Class Codes: H04W 52/60 : using different transmission rates for TPC commands
• CPC Class Codes: Y02D 10/00 : Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A system for rapidly acquiring a spreading code, used in a code division multiple access (CDMA) system, comprises a generator for generating a first long code and a second long code, with each long code having a length of N chips. The first long code is different from the second long code. A transmitter transmits the first long code and the second long code at a first phase angle and at a second phase angle, respectively, on a carrier signal over a communications channel using radio waves. The first long code and the second long code may be transmitted at an in-phase (I) angle and at a quadrature-phase (Q) angle, respectively, on the carrier signal. From the communications channel, an I acquisition circuit and a Q acquisition circuit may acquire, in parallel, the first long code and the second long code from the I angle and the Q angle, respectively, of the carrier signal by searching, in parallel, N/2 chips of the first long code and the second long code.

Claims

1. A code division multiple access (CDMA) subscriber unit comprising:

circuitry configured to establish a connection as part of an access procedure with a network by sending a first CDMA transmission;

wherein the first CDMA transmission is derived from first message bits and pilot bits;

wherein the first message bits are derived from a message used by the subscriber unit to initiate a connection with the network;

circuitry configured to receive a second CDMA transmission in response to the first CDMA transmission;

wherein the second CDMA transmission is derived from second message bits;

wherein the second message bits are derived from a message indicating connection setup information.

2. The CDMA subscriber unit of claim 1 comprising circuitry configured to send a third CDMA transmission in response to the second CDMA transmission;

wherein the third CDMA transmission is derived from third message bits;

wherein the third message bits are derived from a message indicating confirmation of the message indicating connection setup information.

3. The CDMA subscriber unit of claim 1 further comprising circuitry configured to spread at least the message bits with a first spreading code and to spread at least the pilot bits with a second spreading code;

wherein the first and second spreading codes are different spreading codes.

4. The CDMA subscriber unit of claim 3 wherein the different spreading codes are orthogonal codes.

5. The CDMA subscriber unit of claim 3 wherein the spread message bits correspond to a first channel and the spread pilot bits correspond to a second channel.

6. The CDMA subscriber unit of claim 1 wherein the second message bits are recovered from a control channel.

7. The CDMA subscriber unit of claim 1 wherein the first CDMA transmission is derived from at least one PN code sequence.

8. The CDMA subscriber unit of claim 1 wherein the first CDMA transmission is derived from a complex code sequence;

wherein the complex code sequence is derived from at least two PN code sequences.

9. The CDMA subscriber unit of claim 1 wherein the first CDMA transmission is a QPSK transmission.

10. The CDMA subscriber unit of claim 1 wherein the message indicating connection setup information includes channel assignment information.

11. The CDMA subscriber unit of claim 10 wherein the channel assignment information is bearer channel assignment information.

12. The CDMA subscriber unit of claim 1 wherein the first message bits are sent over an access channel.

13. The CDMA subscriber unit of claim 1 further comprising circuitry configured to send a fourth transmission and circuitry configured to receive an indication that the fourth transmission was received;

wherein the first CDMA transmission is transmitted on a condition that the indication is received.

14. The CDMA subscriber unit of claim 1 wherein the pilot bits are transmitted synchronously with the message bits.

15. A method comprising:

sending by a code division multiple access (CDMA) subscriber unit a first CDMA transmission to establish a connection as part of an access procedure;

wherein the first CDMA transmission is derived from first message bits and pilot bits;

wherein the first message bits are derived from a message used by the subscriber unit to initiate a connection with the network; and

receiving by the CDMA subscriber unit a second CDMA transmission in response to the first CDMA transmission and deriving a message indicating connection setup information from the second CDMA transmission.

16. The method of claim 15 further comprising sending by the CDMA subscriber unit a third CDMA transmission in response to the second CDMA transmission;

wherein the third CDMA transmission is derived from second message bits;

wherein the second message bits are derived from a message indicating confirmation of the message indicating connection setup information.

17. The method of claim 15 further comprising spreading by the CDMA subscriber unit at least the first message bits with a first spreading code and spreading by the CDMA subscriber unit at least the pilot bits with a second spreading code;

wherein the first and second spreading codes are different spreading codes.

18. The method of claim 15 wherein the different spreading codes are orthogonal codes.

19. The method of claim 17 wherein the spread message bits correspond to a first channel and the spread pilot bits correspond to a second channel.

20. The method of claim 15 wherein the message indicating connection setup information is recovered from a control channel.

21. The method of claim 15 wherein the first CDMA transmission is derived from at least one PN code sequence.

22. The method of claim 15 wherein the first CDMA transmission is derived from a complex code sequence;

wherein the complex code sequence is derived from at least two PN code sequences.

23. The method of claim 15 wherein the first CDMA transmission is as a QPSK transmission.

24. The method of claim 15 wherein the message indicating connection setup information includes channel assignment information.

25. The method of claim 15 wherein the channel assignment information is bearer channel assignment information.

26. The method of claim 15 wherein the first message bits are sent over an access channel.

27. The method of claim 15 further comprising sending by the CDMA subscriber unit a fourth transmission and receiving by the CDMA subscriber unit an indication that the fourth transmission was received;

wherein the first CDMA transmission is transmitted on a condition that the indication is received.

28. The method of claim 15 wherein the pilot bits are transmitted synchronously with the message bits.