Communication protocol for spread spectrum communication

• US 5,671,219 A
• Filed: 06/07/1995
• Issued: 09/23/1997
• Est. Priority Date: 11/01/1993
• Status: Expired due to Term

• Current Assignee: Intel Corporation
• Original Assignee: Omnipoint Corp. (Deutsche Telekom AG)
• Inventors: Scott, Logan, Jensen, Ryan N., Williams, Claude M.
• Primary Examiner(s): Chin, Wellington
• Assistant Examiner(s): Vu, Huy D.
• Application Number:
  US08/473,746
• Time in Patent Office: 839 Days
• Field of Search: 370/13, 370/17, 370/18, 370/95.1, 370/95.3, 370/110.1, 370/29, 370/310, 370/311, 370/312, 370/313, 370/314, 370/328, 370/345, 370/347, 370/252, 370/276, 370/277, 370/279, 370/280, 370/282, 370/294, 370/522, 370/465, 370/498, 455/38.3, 455/63, 455/69, 455/70, 455/133, 455/134, 455/135, 455/136, 455/53.1, 455/54.1, 455/50.1, 455/52.1, 455/343, 379/58, 379/60, 379/63, 375/200, 375/267
• US Class Current: 370/280
• CPC Class Codes: G10L 19/012 Comfort noise or silence coding
• CPC Class Codes: H04B 7/0805 with single receiver and antenna switching H04B7/0822 takes precedence
• CPC Class Codes: H04B 7/10 Polarisation diversity; Directional diversity
• CPC Class Codes: H04B 7/2618 using hybrid code-time division multiple access [CDMA-TDMA]
• CPC Class Codes: H04B 7/2643 using time-division multiple access [TDMA] H04B7/2615, H04B7/2618 take precedence
• CPC Class Codes: H04B 7/2668 Arrangements for Wireless Code-Division Multiple Access [CDMA] System Synchronisation, for code acquisition H04B1/7075, for code tracking H04B1/7085
• CPC Class Codes: H04L 1/0002 by adapting the transmission rate
• CPC Class Codes: H04L 1/0025 Transmission of mode-switching indication
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: H04L 47/50 Queue scheduling
• CPC Class Codes: H04L 47/522 Dynamic queue service slot or variable bandwidth allocation
• CPC Class Codes: H04L 47/6215 Individual queue per QOS, rate or priority
• CPC Class Codes: H04L 49/90 Buffering arrangements
• CPC Class Codes: H04L 49/901 using storage descriptor, e.g. read or write pointers
• CPC Class Codes: H04W 24/10 Scheduling measurement reports ; Arrangements for measurement reports
• CPC Class Codes: H04W 36/0058 Transmission of hand-off measurement information, e.g. measurement reports
• CPC Class Codes: H04W 36/18 for allowing seamless reselection, e.g. soft reselection
• CPC Class Codes: H04W 36/30 by measured or perceived connection quality data
• CPC Class Codes: H04W 36/36 by user or terminal equipment
• CPC Class Codes: H04W 52/04 TPC
• 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 52/36 : with a discrete range or set of values, e.g. step size, ramping or offsets
• CPC Class Codes: H04W 52/362 : Aspects of the step size
• CPC Class Codes: H04W 52/367 : Power values between minimum and maximum limits, e.g. dynamic range
• CPC Class Codes: H04W 52/38 : TPC being performed in particular situations
• CPC Class Codes: H04W 52/40 : during macro-diversity or soft handoff
• CPC Class Codes: H04W 56/00 : Synchronisation arrangements
• CPC Class Codes: H04W 72/044 : based on the type of the allocated resource
• CPC Class Codes: H04W 72/0446 : Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/20 : Control channels or signalling for resource management
• CPC Class Codes: H04W 74/06 : using polling
• CPC Class Codes: H04W 76/10 : Connection setup
• CPC Class Codes: H04W 8/04 : Registration at HLR or HSS [Home Subscriber Server]
• CPC Class Codes: H04W 92/12 : between access points and access point controllers

Abstract

A simple and flexible over-air protocol for use with a mobile telephone system, having hand-held telephones in a microcell or other type of cellular communication system. A method in which user stations communicate with one or more base stations to place and receive telephone calls, in which the user stations are provided a secure voice or data link and have the ability to handoff calls between base stations while such calls are in progress. Each base station has a set of "air channels" to which it transmits in sequence. The air channels supported by each base station are called that base station'"'"'s "polling loop". A user station receives general polling information on an unoccupied air channel, transmits responsive information to the base station, and awaits acknowledgment from the base station. Each base station may therefore simultaneously maintain communication with as many user stations as there are air channels in its polling loop. The ability of a user station to communicate on any unoccupied air channel makes the protocol air-channel agile, while the stability of user station and base station clocks may define air channels, gaps, and minor frames.

Claims

1. A communication protocol for time division multiple access communication comprising

a major time frame divided into a plurality of minor time frames, said minor time frames collectively capable of supporting a plurality of communication links between a base station and a plurality of user stations,

a control pulse interval in a first one of said minor time frames, whereby a control pulse is transmitted to said base station from a user station in communication with said base station,

means in said base station for measuring a received signal quality of said control pulse,

a base transmission interval in said first minor time frame, whereby a base-to-user spread spectrum signal is transmitted from said base station to said user station using an antenna selected in response to said received signal quality, said base-to-user spread spectrum signal comprising a power adjustment command,

a user transmission interval in said first minor time frame, whereby a user-to-base spread spectrum signal is transmitted from said user station to said base station at a power level determined in response to said power adjustment command.

2. The communication protocol of claim 1 wherein said control pulse, said base-to-user spread spectrum signal, and said user-to-base spread spectrum signal are each transmitted over the same frequency band.

3. The communication protocol of claim 1 wherein said antenna comprises an omnidirectional antenna.

4. The communication protocol of claim 1 wherein said antenna comprises a steered phased array antenna.

5. The communication protocol of claim 1 wherein said antenna comprises a circularly polarized antenna.

6. The communication protocol of claim 1 wherein an internal synchronization pulse is generated by said base station in response to said control pulse.

7. The communication protocol of claim 1 wherein said control pulse is transmitted using a spread spectrum technique.

8. A method for time division multiple access communication comprising the steps of

defining a series of major time frames, each major time frame divided into a plurality of minor time frames,

transmitting with a power level, in a designated minor time frame of a major time frame, a pulse signal from a user station to a base station, said base station capable of communicating with a different user station in each minor time frame of said major time frame,

receiving said pulse signal at said base station,

measuring a received signal quality in response to said pulse signal,

measuring a received signal power of said pulse signal,

selecting a base station antenna in response to said received signal quality,

transmitting over said base station antenna, in said designated minor time frame of said major time frame, a first spread spectrum signal from said base station to said user station, said first spread spectrum signal comprising a power adjustment command based at least in part on said received signal power,

receiving said first spread spectrum signal at said user station,

adjusting said power level at said user station in response to said first spread spectrum signal,

transmitting with said adjusted power level, in said designated minor time frame of said major time frame, a second spread spectrum signal from said user station to said base station, and

receiving said second spread spectrum signal at said base station.

9. The method of claim 8 wherein said step of measuring a received signal quality comprises the step of measuring at least one of a received power, envelope or phase of said pulse signal.

10. The method of claim 8 wherein said power adjustment command comprises a plurality of command bits.

11. The method of claim 8 wherein said power adjustment command comprises one of a discrete set of power adjustment command values.

12. The method of claim 8 wherein said step of adjusting said power level comprises the step of increasing or decreasing said power level by a relative amount indicated by said power adjustment command.

13. The method of claim 8 wherein said pulse signal, said first spread spectrum signal, and said second spread spectrum signal are each transmitted over the same frequency band.

14. The method of claim 8 wherein said base station antenna comprises an omnidirectional antenna.

15. The method of claim 8 wherein said base station antenna comprises a steered phased array antenna.

16. The method of claim 8 wherein said base station antenna comprises a circularly polarized antenna.

17. The method of claim 8 further comprising the step of generating an internal synchronization pulse at said base station in response to said pulse signal.

18. The method of claim 8 wherein said pulse signal is transmitted using a spread spectrum technique.

19. A communication protocol for time division multiple access communication comprising

a major time frame divided into a plurality of minor time frames, said minor time frames collectively capable of supporting a plurality of communication links between a base station and a plurality of user stations,

a control pulse interval in a each of said minor time frames, wherein a control pulse is transmitted to a base station from one of said plurality of user stations using said minor time frame for communication,

means in said base station for measuring a received signal quality of said control pulse,

a base transmission interval in each of said minor time frames, wherein a first spread spectrum signal is transmitted from said base station to said user station using an antenna selected in response to said received signal quality, said first spread spectrum signal comprising a power adjustment command,

a user transmission interval in each of said minor time frames, wherein a second spread spectrum signal is transmitted from said user station to said base station at a power level determined in response to said power adjustment command.

20. The communication protocol of claim 19 wherein said control pulse, said first spread spectrum signal, and said second spread spectrum signal are each transmitted over the same frequency band.

21. The communication protocol of claim 19 wherein said antenna comprises an omnidirectional antenna.

22. The communication protocol of claim 19 wherein said antenna comprises a steered phased array antenna.

23. The communication protocol of claim 19 wherein said antenna comprises a circularly polarized antenna.

24. The communication protocol of claim 19 wherein an internal synchronization pulse is generated by said base station in response to said control pulse.

25. The communication protocol of claim 19 wherein said control pulse is transmitted using a spread spectrum technique.

26. In a spread spectrum wireless communication system employing time division duplex communication, a method comprising the steps of

transmitting, during a designated portion of a time interval, a control pulse from a user station to a base station,

receiving said control pulse at said base station,

generating an internal synchronization pulse at said base station in response to said control pulse,

measuring an indication of link quality in response to said control pulse, including the step of measuring a received signal power of said control pulse,

selecting an antenna for a subsequent spread spectrum transmission from said base station to said user station based upon said indication of link quality, and

commanding said user station to adjust a transmission power in response to at least said received signal power.

27. The method of claim 26 wherein said control pulse is transmitted using a spread spectrum technique.

28. A time frame structure for wireless communication comprising:

a major time frame, and

a plurality of minor time frames in said major time frame, each minor time frame comprising

a first interval wherein an assigned user station transmits a first spread-spectrum user station signal over a designated frequency band to a base station,

a second interval wherein said base station transmits a spread-spectrum base station signal over said designated frequency band to said assigned user station, said assigned user station adjusting a transmission power level in response to receiving said spread-spectrum base station signal, and

a third interval wherein said assigned user station transmits a second spread-spectrum user station signal over said designated frequency band to said base station.

29. In a time division multiple access communication system, a method for communicating comprising the steps of:

defining a plurality of major time frames, each major time frames comprising a plurality of minor time frames, and each minor time frame capable of supporting a communication link between a base station and one of a plurality of user stations,

transmitting, during a first interval of a minor time frame and over a designated frequency band, a spread-spectrum user station signal from a user station to said base station,

receiving said spread-spectrum user station signal at said base station,

measuring at said base station a relative signal quality of said spread-spectrum user station signal,

selecting a base station antenna from among a plurality of base station antennas in response to receiving said spread-spectrum user station signal at said base station,

transmitting, during a second interval of said minor time frame and over said designated frequency band, a spread-spectrum base station signal from said base station to said user station, and

receiving said spread-spectrum base station signal at said user station.

30. The method of claim 29 wherein said step of measuring at said base station a relative signal quality of said spread-spectrum user station signal further comprises the step of measuring at least one of a received signal power, envelope or phase of said spread-spectrum user station signal.

31. In a time division multiple access communication system, a method of communicating comprising the steps of:

(a) dividing each of a series of major time frames into a plurality of minor time frames, said minor time frames collectively supporting communication between a base station and a plurality of user stations,

(b) transmitting, during a first interval of a minor time frame and over a designated frequency band, a spread-spectrum user station signal from a user station to said base station,

(c) receiving said spread-spectrum user station signal at said base station,

(d) measuring at said base station a signal quality of said spread-spectrum user station signal,

(e) selecting at least one base station antenna from among a plurality of base station antennas,

(f) transmitting using said at least one base station antenna, during a second interval of said minor time frame and over said designated frequency band, a spread-spectrum base station signal from said base station to said user station,

(g) receiving said spread-spectrum base station signal at said user station, and

(h) repeating steps (b) through (g) at the occurrence of said minor time frame in each major time frame.