Subscriber RF telephone system for providing multiple speech and/or data signals simultaneously over either a single or plurality of RF channels

• US 5,657,358 A
• Filed: 04/22/1993
• Issued: 08/12/1997
• Est. Priority Date: 03/20/1985
• Status: Expired due to Term

• Current Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Original Assignee: Interdigital Technology Corporation (InterDigital, Inc.)
• Inventors: Panech, Eric, Handzel, Mark J., Morley, Steven Allan, Avis, Graham M.
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): GLUCK, JEFFREY WILLIAM
• Application Number:
  US08/052,013
• Time in Patent Office: 1,573 Days
• Field of Search: 375/53, 375/56, 375/122, 375/356, 455/54.1, 455/55.1, 455/72, 370/32, 370/109, 370/31, 370/50, 358/133, 381/29, 381/30, 381/31, 332/103, 329/104, 379/58, 379/59, 379/61, 379/63, 379/272
• US Class Current: 375/356
• CPC Class Codes: H04B 7/04 using two or more spaced independent antennas
• CPC Class Codes: H04B 7/0865 Independent weighting, i.e. weights based on own antenna reception parameters
• CPC Class Codes: H04J 3/0647 Synchronisation among TDM nodes
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0007 by modifying the frame length
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0057 Block codes H04L1/0061, H04L1/0064 take precedence
• CPC Class Codes: H04L 1/0061 Error detection codes
• CPC Class Codes: H04L 1/0084 Formats for payload data
• CPC Class Codes: H04L 1/06 using space diversity
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence
• CPC Class Codes: H04L 1/1642 Formats specially adapted for sequence numbers
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/188 Time-out mechanisms
• CPC Class Codes: H04L 1/1887 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 5/143 for modulated signals H04L5/1469 takes precedence
• CPC Class Codes: H04W 24/00 Supervisory, monitoring or testing arrangements
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 28/14 : using intermediate storage
• CPC Class Codes: H04W 28/24 : Negotiating SLA [Service Level Agreement]; Negotiating QoS [Quality of Service]
• CPC Class Codes: H04W 28/26 : Resource reservation
• CPC Class Codes: H04W 36/12 : Reselecting a serving backbone network switching or routing node
• CPC Class Codes: H04W 4/18 : Information format or content conversion, e.g. adaptation by the network of the transmitted or received information for the purpose of wireless delivery to users or terminals
• CPC Class Codes: H04W 40/02 : Communication route or path selection, e.g. power-based or shortest path routing
• CPC Class Codes: H04W 52/0216 : using a pre-established activity schedule, e.g. traffic indication frame
• CPC Class Codes: H04W 52/20 : using error rate
• CPC Class Codes: H04W 56/00 : Synchronisation arrangements
• CPC Class Codes: H04W 72/02 : Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/04 : Wireless resource allocation
• 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 72/0453 : Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/12 : Wireless traffic scheduling
• CPC Class Codes: H04W 72/23 : in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/04 : Scheduled access hybrid access H04W74/02
• CPC Class Codes: H04W 76/10 : Connection setup
• CPC Class Codes: H04W 84/00 : Network topologies
• CPC Class Codes: H04W 84/14 : WLL [Wireless Local Loop]; RLL [Radio Local Loop]
• CPC Class Codes: H04W 88/08 : Access point devices
• CPC Class Codes: Y02D 30/70 : in wireless communication networks

Abstract

A toll quality terrestrial wireless digital multiple access terrestrial communication system is disclosed having a base station in communication with telephone lines and with mobile subscriber stations. The system comprises a switching matrix at the base station and set-up means at the subscriber stations. Means are provided for a periodic exchange of information during the course of communication operation concerning the present status for the connection between the base station and a subscriber station, the link quality, power, and timing adjustment thereof and providing adjustment to the subscriber station based thereupon. Base station and subscriber station apparatus are also disclosed including means for periodically exchanging information during the course of communication operation concerning the present status for the connection between the base station and a subscriber station, the link quality, power, and timing adjustment thereof and providing adjustment to the subscriber station based thereupon.

Claims

1. A toll quality terrestrial wireless digital multiple access communication system having a base station in communication with telephone lines and with subscriber stations, the system being capable of simultaneous transmission of forward information signals and reverse information signals over a radio frequency (RF) link between the telephone lines and the subscriber stations on forward and reverse frequency channels, each of the forward and reverse frequency channels being divided into a plurality of time slots, the system comprising:

a switching matrix at the base station and set-up means at the subscriber stations with the base station switching matrix being coupled to the telephone lines for coupling first forward information from the telephone lines as first forward signals, to a selected one of a plurality of compressors and for coupling second reverse signals received from base station decompressors as second reverse information onto the telephone lines, and with set-up means at each subscriber station for setting up first reverse information as first reverse signals and for setting up second forward signals received from a subscriber station decompressor as second forward information for output to a user;

signal compressors at the base station and at the subscriber stations, with the base station signal compressors being connected to the base station switching matrix for generating compressed first forward signals on a time slot in one of said forward frequency channels, said compressed forward signals may be reconstructed at a subscriber station to provide substantially the same information as the first forward signals provided before being compressed with the compressor of each subscriber station being connected to the subscriber station set-up means for compressing first reverse signals from the subscriber station set-up means and for generating compressed reverse signals that may be reconstructed at the base station to provide substantially the same information as the first reverse signals provided before being compressed;

signal decompressors at the base station and at the subscriber stations, with the base station decompressors being connected to the base station switching matrix for decompressing compressed reverse signals received from the subscriber stations over the RF link on the reverse frequency channel and for generating second reverse signals for the base station switching matrix that provide substantially the same information as the first reverse signals provided with the decompressor of each subscriber station being connected to the subscriber station set-up means for decompressing compressed forward signals received from the base station over the RF link on the forward frequency channel and for generating second forward signals for the subscriber station set-up means that provide substantially the same information as the first forward signals provided;

assigning means for assigning a channel/slot for one of the forward and reverse compressed information signals so that it can be transmitted over a respective one of said forward and reverse frequency channels to a respective one of said base station and subscriber stations, said assigning means comprising memory means for maintaining a memory of which channels/slots are so assigned and consulting said memory upon receipt by the base station of the information to be communicated;

a signal combiner connected to the base station compressors for combining compressed forward signals for application to the forward frequency channel with each of the respective compressed forward signals occupying a time slot within the forward frequency channel; and

a transmitter and receiver at the base station and at the subscriber stations, for providing direct communication between the base station and the subscriber stations over the RF link.

22. The invention as in any one of claims 1, 3, 5 or 6, further comprising:

means to provide a periodic exchange of information during the course of communication operation concerning the present status for the connection between the base station and a subscriber station, the link quality, power, and timing adjustment thereof and providing adjustment to the subscriber station based thereupon.

24. The invention as in claim 1 or 3 wherein the compressors compress the signals to a data rate less than 16 kbps and further including modulators at the base station and at the subscriber stations which transmit at least 2 bits per symbol such that at least 2 2-way toll quality conversations can be supported on a combination of a forward and a reverse frequency channel.

25. The invention as in claim 24 wherein said modulators are 4-level phase shift keying (PSK) modulators.

26. The invention as in claim 24 wherein said modulation is a phase shift keying (PSK) modulation of M-ary PSK modulation.

27. The invention as in claim 26 wherein M is at least 4.

28. The invention as in claim 26, wherein the number of M phase levels of M-ary differential PSK modulation is dynamically determined.

29. The invention as in claim 26, wherein said M-ary modulation is achieved by M-ary modulating with a first M-ary modulation level and for M-ary modulating with a second M-ary modulation level, said first and second M-ary modulation levels being different, said first and second M-ary modulation levels resulting in at least one of said time slots having a different time duration.

30. The invention as in claim 24 wherein said modulation is 16-level PSK modulation.

31. The invention as in claim 1 or 4 wherein the compression step compresses the signals to a data rate less than 16 kbps and further including the step of modulating at the base station and at the subscriber stations which transmits at least 2 bits per symbol such that at least 2 2-way toll quality conversations can be supported on a combination of a forward and a reverse frequency channel.

32. The invention as in claim 31 wherein said modulation is 4-level phase shift keying (PSK) modulation.

33. The invention as in claim 31 wherein said modulation is M-ary PSK modulation.

34. The invention as in claim 31 wherein said modulation is 16-level PSK modulation.

39. The invention as in any one of claims 1, 2, 3, 4, 5, 7, 8, 9, 10, 11 or 16 wherein control signals are transmitted by said base station to said subscriber station on said forward frequency channel together with said forward signals.

40. The invention as in any one of claims 1, 7 or 9 wherein said base station further comprises diversity receiving means for receiving the reverse signals from the subscriber stations on the reverse frequency channel such that the effect of multipath fading is at least reduced.

41. The invention as in claim 39 wherein at said base station and subscriber stations error correction coding is performed on said control signals.

42. The invention as in any one of claims 1, 3, 5, 7, 9, 11 or 21 wherein said base station further comprises means for canceling undesirable echo signals.

43. The invention as in claim 1 wherein:

said compressed first forward signals generated by said signal compressor at said base station contain a digital representation of the values of first predetermined parameters of a vocal tract model, said first predetermined parameters characterizing said first forward signals and being used by the signal decompressor at the subscriber stations, and said compressed reverse signals generated by said signal compressor at said subscriber stations contain a digital representation of the values of second predetermined parameters of a vocal tract model, said second predetermined parameters characterizing said first reverse signals and being used by the signal decompressor at the base station.

44. The invention as in claim 1 or 3 wherein said signal compressors compress said signals to a data rate less than 14.6 kbps.

45. The invention as in any one of claims 1, 3, 5, 7, 9, 11 or 21 wherein the information signals received from the telephone lines are digital signals.

46. The invention as in any one of claims 1, 3, 5, or 35 wherein the base station and each subscriber station respectively transmit a control signal to adjust the power to thereby improve link quality between the base station and the respective subscriber station, degradation in link quality below a level resulting in termination of that assigned channel.

47. The invention as in any one of claims 1, 3, 5, 7, 9, 11 or 21 further comprising,

frame synchronization means for frame synchronization across the different frequency channels, and wherein the subscriber stations send their information signals to the base station at a half-duplex rate.

48. The invention as in any one of claims 1, 3, or 36 wherein said compressing of information signals includes compressing voice information signals by block-encoding.

50. The invention as in any one of claims 1, 3, 5, 7, 9, 11 or 21 wherein the base station includes a device which dynamically changes the number of time slots used in a system frame.

51. The invention as in any one of claims 1, 3, 5, 7, 9, 11 or 24 wherein the subscriber station transmits signals during one slot of a system frame and receives the base station signals during another slot of the same system frame.

52. The invention as in any one of claims 1, 3 or 36 wherein the compressors and decompressors of the base station and subscriber station operate using sub-band voice coding.

53. The invention as in claim 1 or 3 wherein the compressors and decompressors of the base station and subscriber station encode and decode information signals at different rates.

54. The invention as in any one of claims 1, 3, 5, 7, 9, 11 or 21 wherein said base station includes an equalizer for equalizing a signal received, and wherein said base station includes a demodulator which demodulates said reverse signals.

55. The invention as in claim 54, wherein said demodulator includes a digital filter and has a self-training mode in which said digital filter is taught the imperfections of a path through which said reverse channel signal passes before reaching said demodulator.

56. The invention as in any one of claims 1, 2, 3, 4, 5 or 6, wherein said assigned time slot is commonly shared by a plurality of said subscriber stations.

2. A method for toll quality terrestrial wireless digital multiple access communication wherein a base station is in communication with telephone lines and with mobile subscriber stations, the method being capable of simultaneous transmission of forward information signals and reverse information signals over a radio frequency (RF) link between the telephone lines and the subscriber stations on forward and reverse frequency channels, each of the forward and reverse frequency channels being divided into a plurality of time slots, the method comprising the steps of:

switching at the base station and setting up at the subscriber stations with the base station switching coupled to the telephone lines for coupling first forward information from the telephone lines as first forward signals to a selected one of a plurality of compressors, and for coupling second reverse signals received from base station decompressors as second reverse information onto the telephone lines, and setting up at each subscriber station for setting up first reverse information as first reverse signals and for setting up second forward signals received from a subscriber station decompressor as second forward information for output to a user;

signal compressing at the base station and at the subscriber stations, with the base station compressing step generating compressed first forward signals on a time slot in one of said forward frequency channels, said compressed forward signals may be reconstructed at a subscriber station to provide substantially the same information as the first forward signals provided before being compressed with the compressing step at the subscriber station compressing first reverse signals from the setting up step and for generating compressed reverse signals that may be reconstructed at the base station to provide substantially the same information as the first reverse signals provided before being compressed;

signal decompressing at the base station and at the subscriber stations, with the base station decompressing step receiving compressed reverse signals received from the subscriber stations over the RF link on the reverse frequency channel and for generating second reverse signals to be switched during said switching step that provide substantially the same information as the first reverse signals provided with the decompressing step at each subscriber station decompressing compressed forward signals received from the base station over the RF link on the forward frequency channel and for generating second forward signals for the subscriber station setting up step that provide substantially the same information as the first forward signals provided;

assigning a channel/slot for one of the forward and reverse compressed information signals so that it can be transmitted over a respective one of said forward and reverse frequency channels to a respective one of said base station and subscriber stations, said assigning step including maintaining a memory of which channels/slots are so assigned and consulting said memory upon receipt by the base station of the information to be communicated;

combining signals from the compressing step at the base station for application to the forward frequency channel with each of the respective compressed forward signals occupying a time slot within the forward frequency channel; and

transmitting and receiving at the base station and at the subscriber stations, for providing direct communication between the base station and the subscriber stations over the RF link.

23. The invention as in claim 2 or 4, further comprising the step of:

periodically exchanging information during the course of communication operation concerning the present status for the connection between the base station and a subscriber station, the link quality, power, and timing adjustment thereof and providing adjustment to the subscriber station based thereupon.

49. The invention as in any one of claims 2, 4 or 6 wherein said compressing of signals includes compressing voice information signals by analyzing the speech content of said voice information signals and producing coefficients and an additional signal which characterize the speech content of said voice information signals.

60. The invention as in any one of claims 2, 4, or 8 further including the step of dynamically changing the number of time slots used in a system frame.

61. The invention as in claim 2 or 4 further including the steps of equalizing a signal received and demodulating the reverse signals.

62. The invention as in claim 61 further including the step of teaching a digital filter the imperfections of a path through which said reverse channel signals passes being received.

3. A base station system for toll quality digital wireless communication with multiple access terrestrial mobile subscriber stations, the base station system communicating at least one information signal from a public switched telephone line over one of a plurality of forward frequency channels at different RF frequencies, each of the forward frequency channels being divided into a plurality of time slots, the base station system comprising:

compressors for compressing the information signal such that the compressed signal may be reconstructed at the subscriber station to provide substantially the same information as the information signal provided before being compressed by the compressor;

a switching matrix for coupling the information signal to a selected one of the compressors;

assigning means for assigning a channel/slot for the compressed information signal so that it can be transmitted over one of the forward frequency channels to a subscriber station, said assigning means comprising memory means for maintaining a memory of which channels/slots are so assigned and consulting said memory upon receipt by the base station system of the information signal to be communicated and then providing said assignment of channel/slot that is not assigned;

a multiplexer for multiplexing the compressed information signal from the selected compressor onto the assigned channel/slot; and

a transmitter for transmitting to the subscriber station over the assigned channel within the assigned slot the compressed signal representative of the information.

4. A method for communication of at least one digital information signal in a toll quality, wireless multiple access public switched radio telephone system between a base station and mobile terrestrial subscriber stations over an RF link having a plurality of forward frequency channels at different RF frequencies, each of the forward frequency channels being divided into a plurality of time slots, the method comprising the steps of:

switching the information to a selective one of a plurality of compressors;

compressing the information signal in the selected compressor such that the compressed signal may be reconstructed at the subscriber station to provide substantially the same information as the information signal provided before being compressed;

assigning a channel/slot for the compressed signal so that it can be transmitted over one of the forward frequency channels to a subscriber station, said assigning step including maintaining a memory of which channels/slots are assigned and consulting said memory upon receipt by the base station of the information signal to be communicated and then based upon a selection routine providing said assignment to a channel/slot that is not assigned;

multiplexing the compressed signal from the selected compressor onto the assigned channel/slot wherein said multiplexing is a time division multiplexing in which the compressed signal is placed in the assigned slot on the assigned frequency; and

transmitting over the forward frequency channel to the subscriber station the allocated channel/slot containing the compressed signal.

5. A base station system for wireless communication with multiple access terrestrial mobile subscriber stations, the base station system communicating at least one data information signal from a public switched telephone line over one of a plurality of forward frequency channels at different RF frequencies, each of the transmit channels being divided into a plurality of time slots, the base station system comprising:

assigning means for assigning a channel/slot for the data information signal so that it can be transmitted over one of the forward frequency channels to a subscriber station, said assigning means comprising memory means for maintaining a memory of which channels/slots are so assigned and consulting said memory upon receipt by the base station of the data information signal to be communicated and then providing said assignment of a channel/slot that is not assigned;

a multiplexer for multiplexing the data information signal onto the assigned channel/slot;

a switching matrix for coupling the data information signal from the public switched telephone line to the multiplexer; and

a transmitter for transmitting to the subscriber station over the assigned channel within the assigned slot the data information signal.

6. A digital toll quality terrestrial communication system for providing a plurality of voice signal channels on a plurality of forward and reverse direction carrier frequencies of a RF telephone system, each of said forward and reverse direction carrier frequencies containing a plurality of slots, each of said forward and reverse direction carrier frequencies having an associated predetermined bandwidth which is designed to accommodate one analog voice signal channel therein, said system comprising:

a base station comprising;

circuit paths for receiving a plurality of forward direction digitized voice signals from a public switched telephone network and at least one reverse direction digitized voice signal from a subscriber station;

a plurality of compressors for respectively compressing each of said forward direction digitized voice signals to form compressed voice signals;

a multiplexer for multiplexing the compressed voice signals onto a dynamically assigned frequency/slot within a single transmit channel bit stream;

a plurality of modulators for modulating each of said forward direction carrier frequencies with said transmit channel bit stream;

a transmitter for RF transmitting said forward direction modulated frequency carriers to at least one subscriber station;

an exchange for switching the digitized voice signals through a respective compressor;

means responsive to an incoming call request for providing a slot/frequency assignment signal indicating which slot and frequency a compressed voice signal is to occupy, thereby assigning a digitized voice signal, as compressed, to a time slot and frequency in said transmit channel bit stream, said means for providing a slot assignment signal including a memory which stores information concerning which slots/frequencies have been so assigned, said means for providing a slot/frequency assignment accessing said memory upon receipt of said incoming call request;

means responsive to said slot/frequency assignment signal for causing said exchange to complete the necessary connections so that an incoming digitized voice signal is routed through a respective compression means to said dynamically assigned time slot in said transmit channel bit stream;

a subscriber station comprising;

a compressor for compressing the reverse direction digitized voice signal to form a compressed voice signal;

a channel controller for placing the reverse direction compressed voice signal into a sequential time slot in a transmit channel bit stream;

a modulator for modulating the reverse direction carrier frequency with said transmit channel bit stream;

a transmitter for RF transmitting the reverse direction modulated frequency carrier to the base station.

7. A toll quality terrestrial wireless digital multiple access terrestrial communication system having a base station in communication with telephone lines and with mobile subscriber stations, the system being capable of simultaneous transmission of forward information signals and reverse information signals over a radio frequency (RF) link between the telephone lines and the subscriber stations on forward and reverse frequency channels, comprising:

a switching matrix at the base station and set-up means at the subscriber stations with the base station switching matrix being coupled to the telephone lines for coupling first forward information from the telephone lines as first forward signals, and for coupling second reverse signals received from the subscriber stations as second reverse information onto the telephone lines, and with set-up means at each subscriber station for setting up first reverse information as first reverse signals and for setting up second forward signals received from a subscriber station set-up means as second forward information for output to a user;

set-up means at each of the subscriber stations for placing the reverse signals on a time slot of one of said reverse frequency channels, whereby said reverse signals may be reconstructed at the base station to provide substantially the same information as the reverse information provided from a user, the set-up means receiving forward information signals over the RF link on the forward frequency channel from the base station as forward signals;

interconnection means at the base station for placing the forward signals on a time slot of one of said forward frequency channels, whereby said forward signals may be reconstructed at a subscriber station to provide substantially the same information as the forward information provided on a telephone line, the interconnection means receiving reverse signals over the RF link on the reverse frequency channel from the subscriber stations as reverse signals; and

means to provide a periodic exchange of information during the course of communication operation concerning the present status for the connection between the base station and a subscriber station, the link quality, power, and timing adjustment thereof and providing adjustment to the subscriber station based thereupon.

8. A method for toll quality terrestrial wireless digital multiple access communication wherein a base station is in communication with telephone lines and with mobile subscriber stations, the method being capable of simultaneous transmission of forward information signals and reverse information signals over a radio frequency (RF) link between the telephone lines and the subscriber stations on forward and reverse frequency channels, the method comprising the steps of:

switching at the base station and setting up at the subscriber stations with the base station switching coupled to the telephone lines for coupling first forward information from the telephone lines as first forward signals, and for coupling second reverse signals received from the subscriber stations as second reverse information onto the telephone lines, and setting up at each subscriber station for setting up first reverse information as first reverse signals and for setting up second forward signals received from a subscriber station decompressor as second forward information for output to a user;

setting up at each of the subscriber stations for placing the reverse signals on a time slot of one of said reverse frequency channels, whereby said reverse signals may be reconstructed at the base station to provide substantially the same information as the reverse information provided from a user, the set-up means receiving forward information signals over the RF link on the forward frequency channel from the base station as forward signals;

interconnecting at the base station for placing the forward signals on a time slot of one of said forward frequency channels, whereby said forward signals may be reconstructed at a subscriber station to provide substantially the same information as the forward information provided on a telephone line, the interconnection means receiving reverse signals over the RF link on the reverse frequency channel from the subscriber stations as reverse signals; and

periodically exchanging information during the course of communication operation concerning the present status for the connection between the base station and a subscriber station, the link quality, power, and timing adjustment thereof and providing adjustment to the subscriber station based thereupon.

9. A base station system for providing toll quality digital wireless multiple access terrestrial communication between telephone lines and subscriber stations, the system being capable of simultaneous wireless transmission of forward information and reverse information over a radio frequency (RF) link between the telephone lines and the subscriber stations on forward and reverse frequency channels, the forward information from the telephone lines being applied to a transmitter and the transmitter transmitting forward signals over the RF link from the base station system to the subscriber stations, and a receiver receiving reverse signals from the subscriber station over the RF link and the reverse information being applied to the telephone lines, the base station system comprising:

switching means for coupling the forward information from the telephone lines as forward signals to the transmitter, and the switching means coupling the reverse signals from the receiver as reverse information to the telephone lines;

interconnection means placing the forward signals on a time slot of one of said forward frequency channels, whereby said forward signals may be reconstructed at a subscriber station to provide substantially the same information as the forward information provided on a telephone line, the interconnection means receiving reverse signals over the RF link on the reverse frequency channel from the subscriber stations as reverse signals; and

means to provide a periodic exchange of information during the course of communication operation concerning the present status of the connection between the base station and a subscriber station, the link quality, power, and timing adjustment thereof and providing adjustment to the subscriber station based thereupon.

10. A method for providing toll quality digital wireless multiple access terrestrial communication using a base station between telephone lines and mobile subscriber stations, the system being capable of simultaneous wireless transmission of forward information and reverse information over a radio frequency (RF) link between the telephone lines and the subscriber stations on forward and reverse frequency channels, the forward information from the telephone lines being applied to a transmitter and the transmitter transmitting forward signals over the RF link from the base station system to the subscriber stations, and a receiver receiving reverse signals from the subscriber station over the RF link and the reverse information being applied to the telephone lines, the base station method comprising the steps of:

switching the forward information from the telephone lines as forward signals to the transmitter, and switching the reverse signals from the receiver as reverse information to the telephone lines;

interconnecting the forward signals on a time slot of one of said forward frequency channels, whereby said forward signals may be reconstructed at a subscriber station to provide substantially the same information as the forward information provided on a telephone line, and interconnecting the received reverse signals over the RF link on the reverse frequency channel from the subscriber stations as reverse signals; and

periodically exchanging information during the course of communication operation concerning the present status of the connection between the base station and a subscriber station, the link quality, power, and timing adjustment thereof and providing adjustment to the subscriber station based thereupon.

37. The invention as recited in claim 8 or 10 further including the step of assigning a channel/slot for the forward signal so that it can be transmitted over the RF link to a subscriber station, said assigning step including maintaining a memory of which channels/slots are assigned and consulting said memory upon receipt by the base station of the information signal to be communicated and then based upon a selection routine providing said assignment to a channel/slot that is not assigned.

38. The invention as in claim 37 further including a compression step which compresses the signals to a data rate less than 16 kbps and further including the step of modulating at the base station and at the subscriber stations which transmits at least 2 bits per symbol such that at least 2 2-way toll quality conversations can be supported on a combination of a forward and a reverse frequency channel.

57. The invention as in any one of claims 2, 3, 8 or 10 further comprising the step of diversity receiving from the subscriber stations on a frequency channel such that the effect of multipath fading is a least reduced.

58. The invention as in any one of claims 2, 4, 8, 10 or 16 further comprising the step of canceling undesirable echo signals.

59. The invention as in any one of claims 2, 4, 8, 10 or 16 further comprising the step of frame synchronizing across the different frequency channels, and wherein the subscriber stations send their information signals to the base station at a half-duplex rate.

11. A subscriber station for providing toll quality digital wireless multiple access terrestrial communication between telephone lines and a base station, the subscriber station and the base station being capable of simultaneous wireless transmission of forward information and reverse information over a radio frequency (RF) link between the telephone lines and the subscriber station on forward and reverse frequency channels, the forward information from the telephone lines being applied to a transmitter and the transmitter transmitting forward signals over the RF link from the base station to the subscriber station, and a receiver receiving reverse signals from the subscriber station over the RF link and the reverse information being applied to the telephone lines, the subscriber station comprising:

set-up means placing the reverse signals on a time slot of one of said reverse frequency channels, whereby said reverse signals may be reconstructed at the base station to provide substantially the same information as the reverse information provided from a user, the set-up means receiving forward signals over the RF link on the forward frequency channel from the base station as forward signals; and

means to provide a periodic exchange of information during the course of communication operation concerning the present status of the connection between the base station and a subscriber station, the link quality, power, and timing adjustment thereof and providing adjustment to the subscriber station based thereupon.

12. The subscriber station of claim 11 further including compressors which compress the signals to a data rate less than 16 kbps and further including modulators at the base station and at the subscriber station which transmit at least 2 bits per symbol such that at least 2 2-way toll quality conversations can be supported on a combination of a forward and a reverse frequency channel.

13. The invention as in claim 12 wherein said modulation is 4-level phase shift keying (PSK) modulation.

14. The invention as in claim 12 wherein said modulation is M-ary PSK modulation.

15. The invention as in claim 12 wherein said modulation is 16-level PSK modulation.

35. The invention as in any one of claims 7, 9 or 11 further including assigning means for assigning a channel/slot for one of the forward and reverse information signals so that it can be transmitted over a respective one of said forward and reverse frequency channels to a respective one of a base station and subscriber stations, said assigning means comprising memory means for maintaining a memory of which channels/slots are so assigned and consulting said memory upon receipt by the base station of the information to be communicated;

a signal combiner connected to the base station for combining forward signals for application to the forward frequency channel with each of the respective forward signals occupying a time slot within the forward frequency channel; and

a transmitter and receiver at the base station and at the subscriber stations, for providing direct communication between the base station and the subscriber stations over the RF link.

36. The invention as in claim 35 further including compressors which compress the signals to a data rate less than 16 kbps, and further including modulators at the base station and at the subscriber stations which transmit at least 2 bits per symbol such that a least 2 2-way toll quality conversations can be supported on a combination of a forward and a reverse frequency channel.

16. A method of using a subscriber station for providing toll quality, digital, wireless multiple access terrestrial communication between telephone lines and a base station, the subscriber station and the base station being capable of simultaneous wireless transmission of forward information and reverse information over a radio frequency (RF) link between the telephone lines and the subscriber station on forward and reverse frequency channels, the forward information from the telephone lines being applied to a transmitter and the transmitter transmitting forward signals over the RF link from the base station to the subscriber station, and a receiver receiving reverse signals from the subscriber station over the RF link and the reverse information being applied to the telephone lines, the method comprising the steps of:

setting up the reverse signals on a time slot of one of said reverse frequency channels, whereby said reverse signals may be reconstructed at the base station to provide substantially the same information as the reverse information provided from a user, and setting up forward signals over the RF link on the forward frequency channel from the base station as forward signals; and

periodically exchanging information during the course of communication operation concerning the present status of the connection between the base station and the subscriber station, the link quality, power, and timing adjustment thereof and providing adjustment to the subscriber station based thereupon.

17. The method of claim 16 further including a compression step which compresses the signals to a data rate less than 16 kbps and further including the step of modulating at the base station and at the subscriber station which transmits at least 2 bits per symbol such that at least 2 2-way toll quality conversations can be supported on a combination of a forward and a reverse frequency channel.

18. The invention as in claim 17 wherein said modulation is 4-level phase shift keying (PSK) modulation.

19. The invention as in claim 17 wherein said modulation is M-ary PSK modulation.

20. The invention as in claim 17 wherein said modulation is 16-level PSK modulation.

21. A base station system for providing wireless multiple access terrestrial data communication between telephone lines and subscriber stations, the system being capable of simultaneous wireless transmission of forward data information and reverse data information over a radio frequency (RF) link between the telephone lines and the subscriber stations on forward and reverse frequency channels, the forward data information from the telephone lines being applied to a transmitter and the transmitter transmitting the forward data information over the RF link from the base station system to the subscriber station, and a receiver receiving reverse data information from the subscriber station over the RF link and the reverse data information being applied to the telephone lines, the base station system comprising:

a multiplexer;

a switching matrix for coupling the forward data information from the telephone lines to the multiplexer, and the switching matrix coupling the reverse data information from the multiplexer to the telephone lines;

the multiplexer placing the forward data information on the time slot of one of said forward frequency channels whereby said forward data information may be transmitted to a subscriber station, the multiplexer receiving from a subscriber station reverse data information over the RF link on the reverse frequency channel; and

means to provide a periodic exchange of information during the course of communication operation concerning the present status of the connection between the base station and a subscriber station, the link quality, power, and timing adjustment thereof, and providing adjustment to the subscriber station based thereupon.