JP2002185399A - Radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a radio communication system in which the signal from any one of remote units being received by a base unit is prevented from having an undue power or governing other unit. SOLUTION: Transmission power of the remote unit is controlled according to a formula; power=A+(B-C), where A is a desired poser being received by the base unit, B is a power transmitted from the base unit, and C is the power of a signal received by the remote unit and measured by the base unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001] Technical Field The present invention relates to a method of encoding two digital signals, in particular, the digital control signals and digital for transmission to a remote unit via a channel comprising a noise due to the base unit in a digital radio telephone It relates to a method of encoding data.

[0002] Wireless communication between the background base unit and one or more remote units of the invention are well known in the art, frequency division multiple access (FDMA) is one of the known methods. In this FDMA system, the available electromagnetic communication spectrum is divided into a plurality of frequency channels, communication between a base unit and a remote unit is performed via one of the frequency channels, and Communication with other remote units takes place over other frequency channels.

[0003] Time division multiple access (TDMA) is also well known in the art. In this TDMA scheme, transmission between a base unit and a first remote unit occurs in a first "slice" of time, and further, transmission between the base unit and a second remote unit. , A second of time, different from said first "part"
In the "part" of

Further, a code division multiple access system (CDM)
In A), communication between the base unit and one or more remote units takes place via spread spectrum transmission in a predetermined frequency domain, in which a specific pseudo-random (PN) code is used. The communication between the unit and the first remote unit is identified, and a different code identifies the communication between the base unit and another remote unit. It should be noted that there are several types of CDMA systems such as direct sequence, frequency hopping, and time hopping. The direct sequence spread spectrum scheme encodes a low rate data stream at the transmitter into a high rate data stream. Thereafter, at the receiver, the higher rate data stream is decoded into a lower rate data stream.

[0005] Setting of a protocol between a remote unit and a base unit prior to communication processing is well known in modem communication technology. Therefore, for example, in packet communication, X.X. The packet size of the remote unit and the base unit is determined according to 25 protocols. Further, in such a modem communication technique, modems having different rated transmission capacities determine the maximum speed applicable to both units prior to communication processing.

In the prior art, it was thought that the transmit power could be adjusted based on a priori knowledge of the transmitted power and the expected received power of the other party. However, such techniques are limited in that they assume fixed channel attenuation.

[0007] It is also known in the prior art that commands are adjusted for dynamic power control by using a feedback loop. However,
In the case of a TDMA system, a delay consisting of a measurement time, a transmission time, and an operation time leads to a large efficiency loss. In addition, the amount of message rate that needs to be allocated for power control can be large, causing capacity loss.

SUMMARY OF THE INVENTION In the present invention, a method for encoding two types of digital data signals is disclosed. The two types of digital data signals consist of a first signal and a second signal transmitted on a noisy channel, each signal being characterized by a bit stream. In this case, N bits from the first signal are mapped to a unique M-bit third signal, M is greater than N, and the number of “1” in the M-bit signal is M /
Less than 2. The M-bit third signal is transmitted when the bit from the second signal is "0", while the complement of the M-bit third signal is transmitted when the bit from the second signal is "1". You.

1. In a method of encoding two types of digital data signals, ie, a first and a second signal, for transmission on a noisy channel, each signal is characterized by a stream of bits, and N bits of the signal are mapped to a third signal of M bits (M> N), and the number of “1” in the third signal of M bits is M / 2.
And the M-bit third signal has a complement, and the M-bit third signal mapped from the N-bit of the first signal when the bit from the second signal is "0". Transmitting a signal and, if bits from the second signal are "1", transmitting a complement of an M-bit third signal mapped from N bits of the first signal.

[0010] 2. Further, the method includes a step of encoding the M-bit third signal with an error correction code prior to a transmission process.

3. The transmitting step further includes transmitting a plurality of concatenated M-bit third signals, wherein each of the adjacent M-bit third signals is mapped from an adjacent N-bit portion of the first signal.

4. Further, the method further includes a step of coding the plurality of M-bit third signals with an error correction code prior to a transmission process.

5. A method of decoding a digital data signal characterized by a stream of bits into a first digital signal and a second digital signal, wherein the decoding step receives M bits from the digital data signal; Is output as the second digital signal when the number of bits is smaller than M / 2, and as the second digital signal when the number of "1" s in the M bits is larger than M / 2. Outputting a "1"; and mapping the received M bits to N bits as the first digital signal.

6. The mapping step further outputs an error signal if the received M bits cannot be mapped to the N bits.

[0015] 7. A method for transmitting and receiving two types of digital data signals on a noisy channel, a first signal and a second signal, wherein each signal is characterized by a bit stream, and further comprising N bits of the first signal. Into an M-bit (M> N) third signal, the number of “1” in the M-bit third signal is smaller than M / 2, and the M-bit third signal has a complement. , When a bit from the second signal is “0”,
An M-bit third signal mapped from the N bits of the first signal is transmitted on the channel, and if a bit from the second signal is "1", Transmitting the complement of the light M-bit third signal to be mapped onto the channel; receiving M bits from the channel; and determining if the number of "1" s in the M bits is less than M / 2. Outputting "0" as the second signal, and outputting "1" as the second signal when the number of "1" s in the M bits is greater than M / 2; Mapping the bits to N bits as the first signal.

8. The mapping step further outputs an error signal if the received M bits cannot be mapped to the N bits.

9. A method of operating a digital radiotelephone comprising a base unit and a remote unit, wherein the method is for wirelessly communicating between the base unit and a remote unit, the base unit comprising a digital control signal and digital data. Signals on the channel, each signal being characterized by a bit stream, and further mapping N bits of the digital data signal into M-bit (M> N) transmission signals, and Transmitting a M-bit transmission signal mapped from N bits of the digital data signal when the number of “1” is smaller than M / 2 and when the bit from the digital control signal is “0”; , M bits mapped from N bits of the digital data signal when a bit from the digital control signal is “1” Comprising the step of transmitting the complement of signal signal.

10. Further, the method includes a step of coding the M-bit transmission signal with an error correction code prior to a transmission process.

11. The transmitting step further includes transmitting a plurality of concatenated M-bit transmission signals, wherein each of the adjacent M-bit third signals is mapped from an adjacent N-bit portion of the digital data signal.

[12] Further, the method includes coding the plurality of M-bit transmission signals with an error correction code prior to transmission processing.

13. Said remote unit decoding a digital data signal characterized by a received bit stream into a first digital signal and a second digital signal, said decoding step receiving M bits from said digital data signal; Is output as a second digital signal when the number of "1" is smaller than M / 2, and when the number of "1" in the M bits is larger than M / 2, the second digital signal is output. Outputting a "1" as a signal and mapping the received M bits to N bits as the first digital signal.

14. The mapping step further outputs an error signal if the received M bits cannot be mapped to the N bits.

[15] A base unit having a first set of functional capabilities and a remote unit having a second set of functional capabilities, wherein the base unit does not have a priori knowledge of the functional capabilities of the remote unit; A method of setting up a full duplex wireless communication link on a common selected frequency channel between units of the:
Transmitting a synchronization signal periodically within a predetermined first selection time, scanning by the remote unit to detect the synchronization signal, and within a second selection time different from the first selection time; Transmitting a first response signal in the common selection frequency channel by the remote unit in response to the detection of the synchronization signal; and in a third selection time different from the first and second selection times, Transmitting, by the remote unit, a first control signal coded with a first code on a common selected frequency channel, the first control signal including the second set of functional capabilities; Receiving the first control signal by a base unit; decoding the first control signal by the base unit to obtain the second set of functional capabilities; The second set compared to the first set by the base unit, determining a set of common functional capabilities in those, the first, second and third
Transmitting, by a base unit, a second control signal coded by the first code in the common selection frequency channel within a fourth selection time different from the selection time, wherein the second control signal is Performing a communication process between said base unit and said remote unit based on a predetermined functional capability from said common set.

16. Further, within a fifth time interval different from the first, second, third and fourth time intervals, an acknowledgment signal is transmitted by the base unit to the selected frequency channel in response to a first response signal from the remote unit. Transmitting within.

17. The first code is a CDMA code.

18. The synchronization signal is encoded by a second code different from the first code.

19. The second code is a CDMA code.

20. The method further includes selecting one of a plurality of frequency channels by the base unit as the selected frequency channel, and the scanning step further includes scanning the plurality of frequency channels once at a predetermined time.

21. There is a base unit having a first set of functional capabilities and a remote unit having a second set of functional capabilities, wherein said base unit does not have a priori knowledge of the functional capabilities of said remote unit; An apparatus for setting up a full duplex wireless communication link on a common selection frequency channel between these units, wherein the base unit periodically transmits a synchronization signal on the common selection frequency channel within a first predetermined selection time. Means for detecting the synchronization signal by the remote unit; and within the common selection frequency channel by the remote unit in response to the detection of the synchronization signal within a second selection time different from the first selection time. Means for transmitting a first response signal to the common terminal within a third selection time different from the first and second selection times. Means for transmitting a first control signal including the second set of functional capabilities and encoded by a first code by the remote unit on an alternative frequency channel, and receiving the first control signal by the base unit Means, means for decoding the first control signal by the base unit to obtain the second set of functional capabilities, comparing the second set to the first set by the base unit, Means for determining a set of common functional capabilities therein, and the common unit selected by the base unit in the common selection frequency channel within a fourth selection time different from the first, second and third selection times. Means for transmitting a second control signal including a set of functional capabilities and encoded by the first code; And means for performing a communication process between the remote unit and the base unit based on force.

22. Further, within a fifth time interval different from the first, second, third and fourth time intervals, an acknowledgment signal is transmitted by the base unit to the selected frequency channel in response to a first response signal from the remote unit. Means for transmitting within.

23. The first code is a CDMA code.

24. The synchronization signal is encoded by a second code different from the first code.

25. The second code is a CDMA code.

26. Further, the apparatus includes means for selecting one of a plurality of frequency channels by the base unit as the selected frequency channel.

27. The detecting means further includes means for scanning the plurality of frequency channels once at a predetermined time.

28. In a method for controlling the power of a remote transmission signal transmitted to a base communication device on a predetermined frequency channel at a predetermined first time by a remote communication device in an open-loop manner, the base device includes the first device. Transmitting a base transmission signal on the frequency channel to the remote device at a predetermined second time different from the time, further receiving the base transmission signal on the frequency channel by the remote device; and receiving the base transmission signal on the frequency channel by the remote device. Measuring the power of the base transmission signal thus obtained, and power = A + (B−
C) controlling the transmission power of the remote transmission signal in the frequency channel according to the following equation:
A indicates the desired power of the remote transmission signal received by the base device, B indicates the power of the base transmission signal, and C indicates the measured power of the base transmission signal as received by the remote device. I have.

29. The parameters A and B are transmitted by the base communication device to the remote communication device.

30. An apparatus for controlling the power of a remote transmission signal transmitted to a base communication apparatus in a predetermined frequency channel at a predetermined first time by a remote communication apparatus in an open loop manner, wherein the base apparatus is configured to control the power of the first time by Means for transmitting a base transmission signal on the frequency channel to the remote device at a different predetermined second time, further comprising means for receiving the base transmission signal on the frequency channel by the remote device; and receiving the base transmission signal on the frequency channel by the remote device. Means for measuring the power of the base transmission signal; and means for controlling the transmission power of the remote transmission signal in the frequency channel according to the equation: power = A + (BC), where A is determined by the base device. Indicates the desired power of the received remote transmit signal, B being the power of the base transmit signal. Indicates chromatography, C indicates the measured power of the base transmission signal when received by the remote device. 31. Means for transmitting a remote transmission signal to the base unit using CDMA on a predetermined selected frequency channel within a predetermined time; and transmitting the remote transmission signal from the base unit on the selected frequency channel within another time different from the predetermined time. Means for receiving the base transmission signal using CDMA, means for measuring the power of the base transmission signal, and means for controlling the transmission power of the remote transmission signal according to the equation of power = A + (BC). Wherein A indicates the desired power of the remote transmission signal received by the base device, B indicates the power of the base transmission signal, and C is the measured power of the base transmission signal as received by the remote device. Is shown.

32. The transmitting means further includes means for transmitting a control signal during a portion of the predetermined time and transmitting a CDMA coded data signal during another portion of the predetermined time.

33. The receiving means further receives a synchronization signal from the base unit.

34. The receiving means further comprising: means for detecting the base transmission signal;
Means for decoding using the MA to generate a decoded base transmission signal.

35. The transmitting means transmits the first control signal and the first data signal within the predetermined time, and the receiving means receives the second control signal and the second data signal within another time.

36. The remote unit can take one of three states: an off state, a standby state, and an on state.

37. When the remote unit is in a standby state, the remote unit transmits only the first control signal and receives only the synchronization signal and the second control signal.

38. The selected frequency channel is selected as one of a plurality of frequency channels.

39. And means for changing transmission to another frequency channel to change to another frequency in response to a request from said base unit.

40. A method of establishing a wireless communication link between a base unit and a remote unit, wherein the base unit periodically transmits a synchronization signal on a predetermined selected frequency channel within a predetermined first selection time; Scanning the synchronization signal by the remote unit and, within a second selection time different from the first selection time, by the remote unit, in response to the detection of the synchronization signal, by a first code in the selected frequency channel. Transmitting a first response signal encoded by the base unit in the selected frequency channel within a third selection time different from the first and second selection times by the first code. And a first control including a second code used in a communication process between the base unit and the remote unit. Transmitting a signal; receiving the first control signal by a remote unit within the third time; and transmitting the signal to the base unit within a fourth selection time different from the first, second, and third selection times. Transmits the data signal encoded by the second code, and outputs the first, second, third, and fourth data signals.
Within a fifth hour different from the hour, the remote unit
Transmitting another data signal encoded by the second code to perform a communication process between the base unit and the remote unit on the selected frequency channel.

41. The synchronization signal is coded as a CDMA code.

42. The first code is a CDMA code.

43. The second code is a CDMA code.

44. The method further includes selecting the selected frequency channel from a plurality of frequency channels by the base unit.

45. The scanning step further includes scanning the plurality of frequency channels once every predetermined time in response to the synchronization signal.

46. Apparatus for establishing a wireless communication link between a base unit and a remote unit, wherein the means for periodically transmitting a synchronization signal within a first predetermined time on a predetermined selected frequency channel selected by the base unit. Means for detecting the synchronization signal by the remote unit; and a second means different from the first selection time.
Means for transmitting, by the remote unit, a first response signal coded with a first code within the selected frequency channel in response to the detection of the clock signal during a selected time; and the first and second selected times. Means for transmitting a first control signal coded with the first code by the base unit in the selected frequency channel within a third selection time different from the first coded control signal. Includes a second code used in a communication process between the base unit and a remote unit, further comprising: means for receiving the first control signal by the remote unit; and Means for decoding the first control signal, and the base unit within a fourth selection time different from the first, second and third selection times. Transmitting a data signal coded by the second code, and by the remote unit by the second code within a fifth time different from the first, second, third and fourth times. Means for transmitting communication between the base unit and the remote unit on the selected frequency channel by transmitting another encoded data signal.

47. The synchronization signal is coded as a CDMA code.

48. The first code is a CDMA code.

49. The second code is a CDMA code.

50. Further, the apparatus includes means for selecting the selected frequency channel from a plurality of frequency channels.

51. The detecting means further includes means for scanning the plurality of frequency channels once every predetermined time by the remote unit in response to detecting the synchronization signal.

52. A spread spectrum wireless communication system for communicating between a base unit and a remote unit, comprising: transmitting a transmission between the base unit and the remote unit on one of a plurality of selected frequency channels.
The base unit transmits within a predetermined time, and the remote unit transmits within another time different from the predetermined time;
Means for changing one of the frequency channels to another frequency channel different from the frequency channel in response to interference in the one of the frequency channels, so that a communication process between the base unit and a remote unit is performed. Is performed on the other frequency channel.

53. The transmitting means transmits a control signal between the base unit and a remote unit during a first portion of the predetermined time and a first portion of the another time;
And means for transmitting a data signal between the base unit and a remote unit at a second portion of the predetermined time and a second portion of the another time.

54. The transmitting means further includes means for transmitting a synchronization signal from the base unit to the remote unit within the predetermined time.

55. A spread spectrum wireless communication method for communicating between a base unit and a remote unit, comprising: transmitting a transmission between the base unit and the remote unit on one of a plurality of selected frequency channels by CDM.
A), wherein the base unit transmits within a predetermined time, the remote unit transmits within another time different from the predetermined time, and furthermore, the base unit transmits the interference in one of the frequency channels. Depending on,
Changing one of the frequency channels to another frequency channel different from the frequency channel, whereby a communication process between the base unit and a remote unit is performed on the other frequency channel.

56. A control signal is transmitted at a first portion of said predetermined time and a first portion of said another time, and a second portion of said predetermined time and a second portion of said another time
A data signal is transmitted in the part.

57. And transmitting a synchronization signal from the base unit to the remote unit within the predetermined time.

58. A base unit for spread spectrum wireless communication with a remote unit, means for transmitting to the remote unit using CDMA on one of a plurality of selected frequency channels within a predetermined time, wherein the means is different from the predetermined time; Means for receiving a transmission from the remote unit using CDMA on one of the plurality of selected frequency channels within another time period, and transmitting on another frequency channel in response to interference on one of the frequency channels. Means for communicating with said remote unit over said another frequency channel.

59. And means for transmitting a control signal during a first portion of the predetermined time and transmitting a CDMA coded data signal during a second portion of the predetermined time.

60. The control signal further includes a synchronization signal and a common control signal.

61. The receiving means further comprises means for detecting a transmission from the remote unit to generate a detection signal, and means for decoding the detection signal using CDMA to generate a decoded transmission signal.

62. A remote unit for performing spread spectrum wireless communication with the base unit, wherein the means for transmitting to the base unit using CDMA on one of a plurality of selected frequency channels within a predetermined time; Means for receiving, from another time, a transmission from the base unit using CDMA on one of the plurality of selected frequency channels;
Means for changing transmission to another frequency channel in response to a request from the base unit to change to another frequency.

63. The transmitting means further includes means for transmitting a synchronization signal during a first portion of the predetermined time and transmitting a CDMA coded data signal during a second portion of the predetermined time.

64. The transmitting means further includes means for receiving a synchronization signal from the base unit.

65. The receiving means further includes means for detecting a transmission from the base unit to generate a detection signal, and means for decoding the detection signal using CDMA to generate a decoded transmission signal.

66. A spread spectrum wireless communication system for communicating between a base unit and a remote unit, the base unit comprising:
Means for transmitting a synchronization signal, a first control signal, and a first data signal to the remote unit using CDMA and a second signal using CDMA at another time different from the predetermined time.
Means for receiving a control signal and a second data signal from the remote unit, wherein the remote unit converts the synchronization signal, the first control signal, and the first data signal using CDMA at the predetermined time. Means for receiving from the base unit and means for transmitting the second control signal and the second data signal to the base unit using CDMA at the different time.

67. The base unit is in communication with a plurality of like remote units.

68. The first control signal is received by the plurality of like remote units.

69. The first data signal is CDMA coded and received by one of the plurality of remote units.

70. The remote unit can take one of three states: an off state, a standby state, and an on state.

71. When the remote unit is in a standby state, it transmits only the second control signal and receives only the synchronization signal and the first control signal.

72. In a base unit in spread spectrum communication with a remote unit, the CDM
A means for transmitting a synchronization signal, a first control signal, and a first data signal to the remote unit using A and a second control signal using CDMA at another time different from the predetermined time. Means for receiving the two data signals from the remote unit.

73. The base unit is in communication with a plurality of like remote units.

74. The first data signal is CDMA coded.

75. A remote unit in spread spectrum communication with a base unit, the CDM
A means for receiving a synchronization signal, a first control signal and a first data signal from the base unit using A, and a second means using CDMA at another time different from the predetermined time.
Means for transmitting a control signal and a second data signal to the base unit.

76. The remote unit can take one of three states: an off state, a standby state, and an on state.

77. When the remote unit is in a standby state, it transmits only the second control signal and receives only the synchronization signal and the first control signal.

78. A method of re-establishing wireless communication between a base unit and a remote unit after an interruption of a communication process, wherein the base unit uses a remote unit between the base unit and the remote unit prior to the interruption of the communication. Transmitting a table of communication channels to be transmitted, wherein the base unit generates a first clock signal having a first clock signal value and the first unit transmits the first clock signal value to the remote unit. Means for generating a second clock signal having a second clock signal value, the second means at the remote unit in case of interruption of the communication process. 2nd generated by
Continuing to count clock signals and synchronizing the second clock signal value with the first clock signal value received by the remote unit prior to the interruption of the communication; Obtaining the entry in the table by applying to the value of the second clock signal in the remote unit; selecting a communication channel associated with the entry in the table by the remote unit; first means in the base unit Continuing the counting of the first clock signal generated by: and applying the same function by the base unit to the value of the first clock signal in the base unit to obtain an entry in the table;
Selecting a communication channel associated with the entry in the table by the base unit, whereby the communication process is reconfigured on the communication channel associated with the entry in the table.

79. Each communication channel is characterized by a plurality of frequency channels within the one channel and a CDMA code.

80. A wireless communication system for communicating between a base unit and a remote unit, wherein the base unit transmits to the remote unit a table of communication channels used between the base unit and the remote unit; Means for receiving a table transmitted by the base unit at the remote unit; means for storing the table received at the remote unit; means for generating a clock signal at the base unit; Means for transmitting the clock signal value to a remote unit at the unit, and in the event of an interruption in the communication link between the base unit and the remote unit, at the base unit a predetermined function of the clock signal at the base unit. Apply to value before Means for obtaining entries in a table, means for selecting a communication channel associated with entries in the table at the base unit, means for receiving the clock signal value at the remote unit, and Means for generating an internal clock signal synchronized to the clock signal value; and, in the event of an interruption in the communication link between the base unit and a remote unit, the same function at the remote unit at the remote unit. Means for applying to the value of the signal to obtain an entry in the table; and means for selecting, in the remote unit, a communication channel associated with the entry in the table, thereby providing an entry associated with the entry in the table. The communication processing is reset on the communication channel to be used.

81. Each communication channel is characterized by a plurality of frequency channels within the one channel and a CDMA code.

82. A method for setting up a wireless communication link between a base unit and a remote unit, the method comprising: selecting one of a plurality of frequency channels at the base unit; Periodically transmitting a synchronization signal into the remote unit; scanning the plurality of frequency channels once at a predetermined time at the remote unit to detect the synchronization signal; Transmitting a first response signal on one of the frequency channels in response to the detection of the synchronization signal within a second selection time different from the first selection time; and transmitting the first and second selection signals to the base unit. Encoding with a predetermined code in one of the frequency channels within a third selection time different from the time And transmitting the channels of communication signal table and the clock signal value, in said remote unit, in the third hour, and receiving the said table signals and the clock signal value,
In the remote unit, within the third time, the table signal and the clock signal value are decoded to obtain a table of the communication channel, and the clock signal generated inside the remote unit is received. Synchronizing to a clock signal value, storing the table at the remote unit, and performing communication between the remote unit and the base unit, wherein the communication link is interrupted. In the remote unit, counting of the clock signal is continued by the clock signal generated inside the unit, and in the remote unit, a predetermined function is applied to the value of the clock signal in the remote unit to fill in the entry in the table. The remote unit then obtains a communication channel associated with the entry in the table. The base unit continues counting the clock signal, and the base unit applies the same function to the value of the clock signal in the base unit to obtain an entry in the table, In the unit, the communication process is reconfigured on the communication channel associated with the entry in the table by selecting the communication channel associated with the entry in the table.

83. Each communication channel is characterized by a plurality of frequency channels within the one channel and a CDMA code.

84. Apparatus for establishing a wireless communication link between a base unit and a remote unit, wherein the means for selecting one of a plurality of frequency channels in the base unit, and the first selection in one of the frequency channels selected by the base unit. Means for periodically transmitting a synchronization signal within a time period, and at the remote unit, one time at a predetermined time for detecting the synchronization signal.
Means for scanning the plurality of frequency channels each time, and at the remote unit, within a second selection time different from the first selection time, a first response signal on one of the frequency channels in response to detection of the synchronization signal. Means for transmitting the first and second signals in the base unit.
Means for transmitting, within a third selection time different from the selection time, a channel table and a clock signal value of a communication signal coded by a predetermined code on one of the frequency channels; Means for receiving the table signal and the clock signal value, and at the remote unit, decoding the table signal and the clock signal value to obtain a table of the communication channel; Means for synchronizing the generated clock signal to the received clock signal value, and in the event of an interruption in the communication link between the base unit and a remote unit, the clock signal at the base unit at the base unit. Means for obtaining an entry in the table by applying a predetermined function to the value of Means for selecting a communication channel associated with an entry in the table at the base unit; means for generating an internal clock signal at the remote unit; and interruption of a communication link between the base unit and the remote unit. Means at the remote unit for applying the same function to the value of the internal clock signal at the remote unit to obtain an entry in the table; and, at the remote unit, a communication channel associated with the entry in the table. Means for resetting the communication process on the communication channel associated with the entry in the table.

85. Each communication channel is characterized by a plurality of frequency channels within the one channel and a CDMA code.

86. Said modifying means further comprising: at the base unit, means for detecting signal interference in one of the frequency channels from the remote unit; and, at the base unit, transmitting a signal message to the remote unit. Means for moving to another frequency channel and means for changing to another frequency channel at the remote unit. 87. The signaling message includes synchronization information.

88. Said altering step further comprises detecting at said base unit interference of a signal on one of said frequency channels from said remote unit;
The base unit transmits a signal message to the remote unit to move to another frequency channel, and the remote unit changes to another frequency channel.

89. The signaling message further includes synchronization information.

90. Means for detecting interference of a signal in one of the frequency channels selected from the remote unit; means for transmitting a signal message to the remote unit to move to another frequency channel; Means for changing to another frequency channel.

91. The signaling message includes synchronization information.

Embodiment 1 FIG. 1 is a block diagram showing a base unit 10.
This base unit 10 is used to communicate with one or more remote units 40 shown in FIG. In a preferred embodiment, the base unit 10 and the remote unit 4
Numeral 0 generally comprises a digital radio telephone 8. Thus, the base unit 10 includes an interface 12 for connection to a public telephone network (PSTN) such as an RJ11 jack or an ISDN interface.

The PSTN portion of the interface 12 performs a PSTN telephone operation such as on / off hook and generation of multiple tones. The signal received by the interface 12 is sent to the interface and multiplexer 18 and then to the application controller 22.

The ISDN portion of the interface 12 translates the ISDN message into a corresponding on / off hook echo, DTMF tone echo, dial tone signal or other signal message.

That is, while the base unit 10 is connected by wire to the telephone switching network, it communicates wirelessly with one or more remote units 40. The base unit 10 includes a speaker horn terminal 14. Thus, the speakerphone terminal 14 allows the base unit 10 to directly communicate with the telephone network via the PSTN / ISDN interface 12 and to wirelessly communicate with one or more remote units 40. . In addition, the base unit 10 has a PSTN / I
It comprises a data terminal interface 16 for receiving digital data for contacting the telephone network by the SDN interface 12 and wireless communication with one or more remote units 40. Thus, for example, data from a source, such as a computer, may be transmitted or received over a telephone network via the PSTN / ISDN interface 12 or wirelessly transmitted or received with one or more remote units 40. The telephone terminal interface 1
It is also possible to supply to the base unit 10 via 6.

The PSTN / ISDN interface 12, speaker horn terminal 14 and data terminal interface 16 are all connected to an interface and a multiplexer 18. The interface and multiplexer 18 are shown in detail in FIG.
6 and acts as an interface for the various signals received from PSTN / ISDN.
It is sent over the telephone network via the interface 12 or processed for transmission to one or more remote units 40.

Further, the base unit 10 comprises a panel 20 composed of lights, switches and a keypad. The signal from the panel 20 is sent to the application controller 22, while the signal from the application controller is supplied to the panel 20. The application controller 22 is shown in detail in FIG.

The application controller 22 performs interface processing with the interface and the multiplexer 18. That is, the functions of the application controller 22 are to perform an interface with the user of the system 8, to read the user's instruction input from the panel 20, and to send a response from the system 8 to the user. It is.

Interface and Multiplexer 1
8 and the application controller 22 are both associated with the base unit transceiver 30. The base unit transceiver 30 has a system clock 35,
Protocol and control unit 32, standby and synchronization unit 34, RF / IF analog unit 36
And at least one set of voice / data processors 38
a and its attached baseband processing unit 28a. The base unit 10 includes the same number of voice / data processors 38a and its associated baseband processing units 28a as one or more remote units 40 operating simultaneously with the base unit 10. Thus, when the base unit 10 is operating simultaneously with the three remote units 40, the transceiver 30
There are three voice / data processors 38 and their associated baseband processing units 28.

Each voice / data processor 38 is connected to its associated baseband unit 28 and also to the interface and multiplexer 18 and the protocol and control unit 32. The baseband processing unit 28 is connected to the RF / IF analog unit 36 and the protocol and control unit 32.

Further, the RF / IF analog unit 36
Is a standby and synchronization unit 34 and a pair of antennas 2
6a and 26b, and these antennas 26a and 26b perform transmission and reception operations, respectively.

Further, the protocol and control unit 32 is connected to the application controller 22.

On the other hand, the remote unit 40 comprises a receiver / terminal 42 comprising a receiver and an interface terminal for receiving data. This receiver terminal 4
2 is connected to an interface and multiplexer 44 similar to the interface and multiplexer 18 of the base unit. The remote unit also comprises a handset panel 46, which is
6 includes lights and switches. This handset panel 4
6 is an application controller 2 similar to the application controller 22 in the base unit 10.
2 connected. Further, the application controller 22 is connected to the interface and the multiplexer 44 as in the base unit 10.

The remote unit 40 also includes a remote unit transceiver 50. The remote unit transceiver 50 comprises a protocol and control unit 52, similar to the transceiver 30 of the base unit, and this unit 52 is also configured similarly to the protocol and control unit 32 of the base unit 10.

Further, the remote unit transceiver 5
0 comprises a standby and synchronization unit 34,
This unit 34 is identical to the standby and synchronization unit 34 of the base unit 10. Also, the remote unit transceiver 50 comprises an RF / IF analog unit 56, which is also similar to the RF / IF analog unit 36 of the base unit transceiver 30, and is connected to a transmit / receive antenna 58a and a receive antenna 58b.

The remote unit transceiver 50 further includes a single audio data processor 38a and its associated baseband processing unit 28a. The voice / data processor 38 and its associated baseband processing unit 28a are identical to the voice / data processor 38a and its associated baseband processing unit 28a in the base unit transceiver 30.

Thus, the remote unit transceiver 50 comprises a protocol and control unit 52, a standby and synchronization unit 34, an RF / IF analog unit 5
6. It comprises a voice / data processor 38a and a baseband processing unit 28a. Furthermore, the connections between these units are the same as the connections between the corresponding components in the base unit transceiver 30. That is, the protocol and control unit 52 includes the application controller 22 and the voice / data processor 38a.
And a baseband processing unit 28a, and a standby and synchronization unit 34. Also, voice /
The data processor 38a includes the baseband processing unit 2
8a and the interface and multiplexer 44. Also, the baseband processing unit 28a
Is connected to an RF / IF analog unit 56, which is connected to the standby and synchronization unit 34 and to the antennas 58a and 58b.

FIG. 3 shows the base unit transceiver 30.
3 is a detailed block diagram of the RF / IF analog unit 36 of FIG. The function of the RF / IF analog unit 36 is to convert the frequency of the signal transmitted or received by the antennas 26a and 26b from a radio frequency to an intermediate frequency. In addition, the unit 36 has a power control capability for controlling the transmission power of the transmission signal. Further, unit 36 modulates and demodulates the in-phase and quadrature-phase components of the baseband signal.

The unit 36 comprises two sets of transmitting / receiving antennas 2
6a and 26b are shown. By using these two antennas 26 (a and b) and the corresponding two sets of circuits, one antenna can be placed in a "dead spot" where the other antenna transmits and receives the necessary signals to the remote unit 40. Is guaranteed to be located. The signal received by one of the antennas 26 is sent to an RF filter and low noise amplifier (LNA) 70a, where the signal is filtered and amplified. Next, the output of the RF filter and the LNA 70a is supplied to an RF-IF down converter 72a.
The function of this RF-IF downconverter 72a is to convert the received RF signal into an intermediate frequency signal.
Such conversion from the RF-IF depends on the difference frequency supplied to the RF-IF downconverter 72a. Further, such a difference frequency is generated by the frequency synthesizer 74 depending on the frequency selection input signal.

Thereafter, the RF-IF down converter 72
From a supplies the intermediate frequency to the IF filter and amplifier 76a. The function of this IF filter and amplifier 76a is to filter and amplify the received IF signal. Further, the IF filter and amplifier 76a increases the gain of the filtered signal based on the gain control signal supplied thereto.

Next, the amplified and filtered IF
The signal is sent to I / Q demodulator 78a. The I / Q demodulator 78a is an in-phase and quadrature-phase demodulator, and generates a baseband frequency signal as an output. The demodulation of the input signal is performed based on the IF frequency signal supplied from the temperature compensated crystal oscillator 82. Then, the baseband frequency signal is supplied to the RRC MF 80a. This R
RC MF80a is root raised
A cosine signal adaptive filter whose output is a positive or negative impulse signal for each of the in-phase and quadrature-phase components of the signal in the absence of carrier phase error. The in-phase and quadrature components are composed of complex signals.

Similarly, the signal from the antenna 26b is supplied along the same second circuit. First, the antenna 26
The signal from b is sent to the RF filter and LNA circuit 70b. Next, the output from the RF and LNA circuit 70b is supplied to the RF-IF down converter 72b. Further, the difference frequency generated by the frequency synthesizer 74 is sent to the RF-IF down converter 72b.
After that, the output of the RF-IF down converter 72b becomes I
It is supplied to the F filter and amplifier 76b, and its gain is also controlled by the same gain control signal as that supplied to the IF filter and amplifier 76a.

Next, the IF filter and the amplifier 76b
Are subjected to in-phase and quadrature-phase demodulation by an IF I / Q demodulator 78b. The in-phase and quadrature-phase demodulation processes are performed based on the IF frequency signal supplied from the temperature-compensated crystal oscillator 82. Then, if I
The output of the / Q demodulator 78b is sent to the RRC MF circuit 80b.

In the transmission state, a binary signal of ± 1 corresponding to the in-phase and quadrature-phase components of the “spread” data signal (to be described in detail later) is supplied to the RRC filter 84. When this input signal is +1 or -1, RRC
84 generates a positive or negative power raised cosine signal, respectively. Thereafter, the output of this RRC filter 84 is RFI /
The signal is sent to a Q modulator 86, which directly converts the raised cosine signal to a radio frequency modulated signal for transmission. On the other hand, the output of the frequency synthesizer 74 that determines the radio frequency signal selected to be modulated and the output of the TCXO 82 that determines the RF frequency in the modulation are supplied to the mixer 88.
The output of the mixer 88 is sent to the RF I / Q modulator 86 and modulated by the output of the RRC filter 84.

Further, the output of the RF I / Q modulator 86 is supplied to an RF filter and an amplifier 90 whose amplifying part has a gain controlled by the gain control signal. Thereafter, the output of the RF filter and amplifier 90 is applied to RF linear amplifier 92a for transmission from antenna 26a.
Sent to In addition, the output of RF filter and amplifier 90 is provided to second RF linear amplifier 92b for transmission via antenna 26a after a delay of "chip" time Tc by delay circuit 94. In this way, two types of signals are generated (one signal is obtained by delay from the other signal), which is sent to the remote unit 40 and combined. In this case, since the two types of signals are delayed, reception at the remote unit 40 with a single antenna is possible.

A frequency synthesizer 74 generates a difference frequency between the RF and IF frequencies. This difference frequency is calculated by the synthesizer 74.
Varies according to the frequency selection signal supplied to. Thus,
The frequency synthesizer 74 operates over all frequency bands. When the generator 74 can generate both the difference frequency (supplied to the RF-IF converter 72) and the RF frequency selected for transmission, and can switch these signals quickly , The mixer 88 is unnecessary.
In such a case, the selected RF frequency output of the combiner 74 can be directly supplied to the RF I / Q modulator 86.

FIG. 4 is a detailed block diagram of the RF / IF analog unit 56 of the remote transceiver unit 50. Similar to the RF / IF analog unit 36, the RF / IF
The IF analog unit 56 includes an antenna 58a or 58b for receiving a signal. In this case, the received signal is supplied to an RF filter and a low noise amplifier 70 for filtering and amplifying the received RF signal. Further, a signal is supplied from the RF filter and LNA circuit 70 to the RF-IF down converter 72. The RF-IF down converter 72 converts the received RF signal into an intermediate frequency signal based on the difference frequency signal generated by the frequency synthesizer 74. The frequency synthesizer 74
Can be selected by the frequency selection signal. Then, the RF-IF down converter 72
From the IF signal to an IF filter and amplifier 76 whose gain is controlled by a gain control signal. Next, the output of the IF filter and the amplifier 76 is
The signal is supplied to the I / Q demodulator 78.

The IF I / Q demodulator 78 also receives the IF frequency signal generated by the temperature compensated crystal oscillator 82. After that, the in-phase and quadrature-phase signals demodulated by the IF I / Q demodulator 78 are sent to the RRC compatible filter 80. When there is no carrier phase error, the output of the RRC adaptive filter 80 is a positive or negative impulse representing a binary signal of ± 1 corresponding to each of the in-phase and quadrature-phase components of the signal.

The transmitter of the RF / IF analog unit 56 receives the "spread" signal from the baseband processing unit 28a. This signal is sent to an RRC filter 84, which outputs a positive or negative root raised cosine signal generated corresponding to the binary in-phase or quadrature component of ± 1 in the "spread" signal. I do. Thereafter, the output signal of the RRC filter 84 is supplied to the RF I / Q modulator 86. Also, the output of the oscillator 82 and the output of the frequency synthesizer 74 are sent to a mixer 88, which mixes the RF required to be supplied to an RF I / Q modulator 86.
Generate a modulated signal. Thus, the RF I / Q modulator 86
Is supplied to an RF filter and amplifier 90 by R
It becomes an F modulation signal. Further, the RF filter and amplifier 90 includes an amplifier whose gain is controlled by a gain control signal. After that, the output of the RF filter and the amplifier 90 is sent to the RF linear amplifier 92, and further sent to the transmission antenna 58b.

FIGS. 5a to 5c are detailed block diagrams of the standby and synchronization unit 34 described above. The standby and synchronization unit 34 comprises a part for capturing and verifying the signal (FIG. 5a), a part for synchronizing the signal (FIG. 5b) and a part for detecting the signal (FIG. 5c).

That is, FIG. 5a shows the acquisition and verification unit 100 of the standby and synchronization unit 34. The acquisition and verification unit 100 comprises a preamble adaptive filter 102 which receives the output of the RRC MF circuit 80 as its input. The function of this preamble adaptive filter circuit 102 is to detect the preamble portion of the SYNC signal generated by the base unit 34 or the preamble portion of the PA1 signal generated by the remote unit (described in detail below). The output of the preamble adaptive filter circuit 102 is sent to the energy detection circuit 104. This energy detection circuit 104
Operates to obtain the magnitude of the signal from the in-phase and quadrature components. Next, the output of the energy detection circuit 104 is sent to the threshold value detection circuit 106. The threshold detection circuit 106 operates to detect the presence or absence of a preamble signal. Generally, the threshold is initially set higher to prevent false recognition, and then set lower to increase the detection probability. Further, the output of the threshold detection circuit 106 is supplied to the verification counter 108. This verification counter 1
08 can optionally feed back to the threshold detection circuit, and the threshold detection circuit can be controlled in a feedback loop. Verification counter 1
The output of 08 is an enable signal, which is used in other components of the standby and synchronization unit 34. For example, if the signal received by the RF / IF analog unit 36 or 56 is a collect signal, the enable signal will be high.

FIG. 5b shows the synchronization part 120 of the standby and synchronization unit. Synchronization section 120 comprises a pseudo-random (PN) code generator 134, which receives a code select signal as its input. This PN code generator 134 generates a PN code determined by the code selection signal. In addition, the generator is １ ／ of the code selected by the code selection signal.
First complex multiplier 122a whose phase is earlier by "chip" time
Generate the code supplied to PN code generator 13
4 also generates a code that is provided to a second complex multiplier 122b that is one-half "chip" time behind the code selected by the code select signal.

The output of the RRC adaptive filter circuit 80 is supplied to the first and second complex multipliers 122a and 122a.
b. Further, the complex multiplier 122a
And 122b are output from low pass filters 124a and 1b.
24b. Then, the low-pass filter 12
The output of 4a and 124b is
a and 126b. The low pass filter and energy detection circuit 126 (a and b) function to determine the magnitude of the signal from the in-phase and quadrature components. Next, the outputs of the energy detection circuits 126a and 126b are supplied to a comparator 128. Comparator 1
The output of 28 is a differential signal, which is sent to the loop filter 130. Further, the enable signal from the verification unit 100 is also supplied to the loop filter 130. This loop filter works when the enable signal is high. Further, the output of the loop filter 130 is sent to the control clock 132, and then returns to the PN code generator 134. In this way, the PN code generator 134 is kept in synchronization by the delay locked loop. The low pass filters 124 (a and b) have a bandwidth near the bit rate and can be provided as an integrating and dumping circuit. That is, the integration and dump circuit is an example of a simple implementation of a low pass filter. The control clock 132 drives the system clock 35.

FIG. 5c shows the modulation and demodulation section 140 of the standby and synchronization unit 34. The modulation and demodulation unit 140 receives a signal from the RRC compatible filter circuit 80. This signal is further converted to a first complex multiplier 142
sent to a. The output of the PN code generator 134 is also sent to the first complex multiplier 142a. Furthermore, the first
The output of the complex multiplier 142a is a first low-pass filter 144a.
Supplied to Next, the signal is sent from the first low-pass filter 144a to the first 1-bit delay circuit 146a. Thereafter, the output of the eleventh bit delay circuit 146a is sent to a first conjugate multiplier 148a to which the output of the low-pass filter 144a is supplied. Further, the first conjugate multiplier 148
The output of a is supplied to the multipath combiner 150. Thereafter, the signal is passed from the multipath combiner 150 to a threshold detector 152, which generates a binary data signal.

The signal from the RRC MF circuit 80 is also sent to a second path comprising a second complex multiplier 142b, to which the output of the PN code generator 134 is also supplied. The output of the second complex multiplier 142b is sent to a second low-pass filter 144b. Further, the output of the second low-pass filter 144b is connected to a second one-bit delay circuit 146b.
Supplied to Thereafter, the output of the one-bit delay circuit 146b is sent to a second conjugate multiplier 148b, to which the output of the second low-pass filter 144b is also supplied. Next, the output of the second conjugate multiplier 148b is sent to the multipath combiner 150 described above. That is, the standby and synchronization unit 34 is
When used with the RF / IF analog unit 36, two paths are provided for signals from the two RRC MF circuits 80a and 80b. In addition, the standby and synchronization unit 34 is connected to the remote unit transceiver 50.
When the base unit 10 transmits two signals that are delayed between each other by a single chip, the multipath combiner 150 described above is used.

The data detecting section 140 also comprises a differential encoder 160 for receiving binary data from the baseband processing unit 28a. The output of the differential encoder 160 is sent to a complex multiplier 162 to which the output of the PN code generator 134 is also supplied. The output of complex multiplier 162 is a "spread" signal, RF / I
It is sent to RRC filter 84 for transmission by F analog unit 36 or 56.

The baseband processing unit 28 includes an acquisition and verification unit (shown in FIG. 5a) and a synchronization unit (fifth embodiment).
b) and a data detection unit 140 (shown in FIG. 5c).
Similar to 4. The difference is that the baseband processing unit operates while the remote unit 40 and the base unit 10 are in communication, as will be described later. In contrast, the standby and synchronization unit 34 operates only when the remote unit 40 is in the standby mode.
However, since the various components of the baseband processing unit 28a are similar, if not identical, to the standby and synchronization unit 34, the baseband processing unit 28a in the remote unit 40 and the standby and synchronization unit 3
4 can be combined into a single unit.

Further, the voice / data processor 38a can be a well-known CODEC standard. Therefore,
The voice processor portion of voice / data processor 38a can be an ADPCM processor. In addition, as described below, each manufacturer of the remote unit 40 and the base unit 10 can provide a proprietary voice code.

The protocol and control unit 52 is a microcomputer capable of storing and executing a program. In addition, this unit receives signals from the system clock 54 or 35 and generates the necessary control signals such as frequency select signals, code select signals and gain control signals.

FIG. 6 is a block diagram of the interface and multiplexer 18. As described above, interface and multiplexer 44 is similar to interface and multiplexer 18. However, the interface and the multiplexer 18 are connected to the PSTN /
The difference is that it is connected to the ISDN interface 12 to communicate with the central processing unit of the telephone network.

The interface 18 is the multiplexer 1
80, and in this multiplexer, the PSTN / IS
Signal exchange with the DN interface 12 is performed. This multiplexer 180 is a switch matrix 1
A signal is output to 82. That is, the multiplexer 18
0, all signals from the data terminal 16 and the speaker horn terminal 14 are sent to the switch matrix 182.
The switch matrix 182 is, as the name implies, a switch for switching signals supplied to the audio / data processor 38a.

The switch matrix 182 connects the voice / data processor 38a to either the data terminal 16 or the speakerphone terminal 14 for local connection with the remote unit 40, or connects to the PSTN / ISDN interface 12 Make a connection to the telephone network via the remote unit 40. Further, the switch matrix 182 can connect the data terminal 16 or the speakerphone terminal 14 to establish a connection with the telephone network via the base unit 10.

The interface / multiplexer 18 supplies a control signal to the multiplexer 180 and outputs the control signal (either PSTN or ISDN signal).
And a control unit 184 that supplies a signal to the voice / data processor 38a by supplying it to the switch matrix 182. This control unit receives instructions from the application controller 22 described above. Further, the interface and multiplexer 18 receives a tone generation signal (corresponding to the PSTN line) or a signal message (corresponding to the ISDN line) directly from the application controller 22.

FIG. 7 shows the application controller 2
2 is a block diagram of FIG. The application controller 22 includes an application processor 190. Data from the base unit panel 20 or the remote unit panel 46 is received by the application processor 190. That is, the panel 20 or 4
6, the application processor 190 sends a signal to the PSTN / ISDN interface to activate the appropriate row or column of the DTMF / pulse generator (PSTN line compatible), or
Formats a signal message (ISDN line compatible). In each case, the signal is sent to the switch matrix 182 of the interface and multiplexer 18.

In the case of an outgoing call, the application processor 190 transmits the off-hook signal from the BS panel 20 or the protocol and control unit 3.
2 from the remote unit 40 requesting the call.
The application processor 190 then communicates via the interface and multiplexer 18 with the PSTN /
It notifies the ISDN interface 12 and generates an appropriate signal (for PSTN line) or message (for ISDN line). A similar procedure is used for dial number notification.

For inbound calls, PSTN / IS
The DN 12 generates an audible notification sound. In this case, the notification message is sent to the protocol and control unit 32 via the interface and multiplexer 18 and the application controller 22, and the notification processing of the remote unit 40 is performed. afterwards,
When the call is answered, the above-described off-hook operation is performed.

Operation Next, the operation of the communication system 8 including the base unit 10 and one or more remote units 40 will be described. As mentioned above, the system 8 is particularly suitable as a digital radio telephone and is suitable for operation in the electromagnetic radiation spectrum range between 902 MHz and 928 MHz. This region is shown in FIG.

The frequency spectrum from 902 MHz to 928 MHz is divided into a plurality of frequency channels.
Each has a bandwidth of about 1.3 MHz. Therefore, about 20 frequency channels can be selected. Also, communication between the base unit 10 and all remote units 40 associated therewith is effective in one of these selected frequency channels.

Further, within the selected frequency channel, the base unit 10 and the associated remote unit 40 communicate via a pseudo-random code or a PN code using CDMA. Thus, for example, when the base unit 10 is communicating with the first remote unit 40a, the base unit 10 transmits and receives on the selected frequency channel and communicates with the remote unit 40a via the first PN code. Communicate with further,
When the base unit 10 is communicating simultaneously with the second remote unit 40b, the base unit 10 communicates with different PN codes on the same selected frequency channel.

Communication between the base unit 10 and each remote unit 40 is performed by the TDMA technique. FIG. 9 shows one or more remote units 4 from the base unit 10.
The timing when transmitting and receiving signals to 0 is shown. That is, in the selected frequency channel, the base unit 10 transmits the common signal channel (CSC).
-B) transmission in the time part consisting of the guard time and the user channel (UC-B) part followed by the guard time. The transmission by each of the remote units 40 is then
This is performed in a time domain consisting of a common signal channel (CSC-R) section divided by the following, followed by a guard time, a user channel (UC-R) section, and a guard time. One frame is constituted by such an operation. Thereafter, such a sequence of timing is repeated, and the base unit 10 transmits in the time domain,
Then, one or more remote units 40 transmit in that time domain.

FIG. 10 shows the timing of various signals transmitted by the base unit. In this case, C
The SC-B signal is further divided into a SYNC section and a DATA section. In the SYNC section, the signal is further divided into SW1 and SW2 signals. SW1
The signal is a synchronization signal. Also, this SW1 signal is generated based on a PN code that is specific to base unit 10 and known by all valid remote units 40. Further, as will be described later, the SW2 signal is the same as SW1 or the reverse signal of SW1. Furthermore, CSC-B
The base unit 10 allocates a PN code to the remote unit 40 and transmits communication between the base unit 10 and the remote unit 40 to a user channel (UC-
B and UC-R).

In the UC-B portion of the signal transmitted by the base unit 10, the UC-B signal is further divided into a user signal channel (USC-B) and a user bearer channel (UBC-B). . USC-
B is further divided into a channel control message (CCM) section containing control information such as power control and a data area containing control signal information such as a signal message. In the case of a digital radio telephone, the signaling message is the number of dials. The UBC-B section includes a message or data transmitted from the base unit 10 to the remote unit 40.

In a preferred embodiment, the message between the remote unit 40 and the base unit 10 spans many frames, and the following definitions are used to demarcate the message. That is, there are a normal frame composed of CSC-B, UC-B, CSC-R and UC-R as described above, a minus frame composed of eight normal frames, and a major superframe composed of 16 normal frames.

The relative polarity of the SW1 and SW2 signals distinguishes the timing between the normal frame and the minus-per frame as follows.

SW1 SW2 Frame Type 0 0 Normal 0 1 Minor Super Thus, the SYNC part of CSC-B is composed of “00” frame units, and is composed of “01” eight frame units. The start of the major frame is USC-B DAT
This is performed by transmitting a message including a frame number by the base unit 10 in the part A.

FIG. 11 shows the detailed timing of the IF frequency signal portion transmitted by each remote unit. The CSC-R section is divided into a PA1 section and a CS-R section. This PA1 part is used for synchronization information, and the CS-R
The unit functions as a control channel. Further, the above UC
The -R unit is divided into a PA2 unit, a USC-R unit, and a UBC-R unit. This PA2 part is used for synchronization information,
The USC-R unit is similar to the USC-B unit in that its area includes control information such as signal properties and signal messages. Further, the UBC-R unit is the same as the UBC-B unit transmitted by the base unit 10,
The CR section is data or a message transmitted by the remote unit 40 to the base unit.

Setting Up a Communication Link Here, as an example, consider a case where the base unit 10 communicates with a single remote unit 40. The setting of the communication link between the base unit 10 and the remote unit 40 in this case is as follows. That is, the base unit 10 periodically transmits a SYNC signal (consisting of SW1 and SW2) in the CSC-B portion of the assigned time slot. This can be said throughout the selected frequency. Further, as an example, consider a case where a frequency is selected in the fourth frequency channel. Also in this case, the SYNC signal is PN-coded (for simplicity, the code index is set to 0). Thus, S
The YNC signal (both SW1 and SW2) is coded by the base unit 10 with the PN code index 0 and transmitted.

As is well known, a PN code is a series of chips. In a preferred embodiment, the PN code corresponding to the SYNC signal has a length of 8 × 32 = 256 chips, of which 128 chips correspond to the in-phase signal and the remaining 128 chips correspond to the quadrature signal. Corresponding to That is, 16 chips correspond to 1 bit for each phase. Thus, SYNs each having an associated index
The combination of _{2 256} possible PN code exists for the C signal. For example, an index of a PN code equal to 0 corresponds to a PN code of “100... 01”.

The remote unit can take one of three possible states: on, standby, and off.

When the remote unit 40 is turned on, this unit will have the PN code of the base unit, ie,
In this case P with an index equal to an index of 0
A default state for searching for a signal having the N code is set. The remote unit 40 then starts scanning the frequency spectrum on a frequency channel equal to zero. This is done by the protocol and control unit 52 described above, which generates a frequency selection signal to cause the combiner 74 to generate a difference frequency, such that the RF frequency in the channel equal to zero is converted to an intermediate frequency. To The protocol and control unit 52 also generates a code select signal so that the PN code equal to an index of 0 is
34. In such a state, the above-described enable signal is generated. However, if the SYNC signal is not found after a predetermined time, P
The CU 52 generates another frequency select signal to transfer to a frequency channel equal to one.

Thus, when the remote unit 40 reaches a frequency channel equal to four, a SYNC signal is found, and the remote unit 40 sends a request signal to the frequency channel equal to four in the CS-R part of the CSC-R time frame. Send a message. The transmission of the request signal message by the remote unit 40 upon recognizing such capture of the SYNC signal may also result in a P with an index equal to zero.
It is coded in a PN code derived from the N code.

In response to receiving a request signal message from the remote unit 40, ie, during a message or data exchange between the base unit 10 and the remote unit 40, the base unit 10 transmits the PN code used in the UC transmission. An assignment signal message is transmitted to it. The transmission of the assignment signal message by the base unit 10 is based on the DAT of the CSC-B timing part.
This is performed in part A, and is encoded into a PN code having an index equal to 0. Thus, for example, when base unit 10 receives a request signal message from remote unit 40, base unit 10 commands that the next communication be processed using a PN code with an index equal to 10. The PN code used during data communication can have a different structure than the PN code for the SYNC signal described above. In a preferred embodiment, PN
The code is 65535 chips long and chips corresponding to in-phase and quadrature signals alternate. In addition,
There are 16 chips per bit for each phase. Thereafter, a PN code message with an index equal to 10 is coded with a PN code with an index equal to 0 and transmitted on a CSC-B time slot, in particular on a DATA time slot. (Note that if the base unit 10 is communicating with another remote unit 40 at the same time, a different PN code is assigned to the communication of the remote unit 40.) The remote unit 40 transmits a signal from the base unit 10 to the CSC-B. The data part of the time slot is received and the information is decoded. Thereafter, the base unit 10 transmits in its UC-B portion and the remote unit 40
Is transmitted in its UC-R portion, the message portion of the communication between the base unit 10 and the remote unit 40 is processed using a PN code with an index equal to 10.

Further, in the process of shifting from the OFF state to the standby state, the PCU 52 generates a frequency selection signal for the synthesizer 74 to scan the frequency channel (0-20), and generates the PN code of the SSU 34. A code selection signal is sent to the detector 134 to search for a PN having an index equal to 0. This frequency selection signal is changed if the preamble MF 102 does not find one that matches the SYNC signal. Thus, when a SYNC signal is found, remote unit 40 is maintained in a standby state and only SSU 34 operates.

The communication between the base unit 10 and the plurality of remote units 40 is also the same as described above. That is,
If the remote unit 40 needs to start a communication process, or if the unit 40 is in a standby state, it scans the frequency channel while searching for the SYNC pulse. After that, the unit 40 becomes the CSC-
Send to the CS-R part of R. Also, base unit 1
0 transmits an assignment signal message having a specific PN code index in the DATA part of the CSC-B timing part. The PN code assigned by the base unit 10 is used in transmitting both the UC-B and UC-R portions. As a result, as described above, each remote unit 40 has a common signal channel portion,
That is, the CSC-R portion is temporarily obtained. Thereafter, in the other remote units 40, signal transmission to the base unit 10 on the CSC-R portion is free. That is,
Once the remote unit 40 has been assigned its PN code, communication on the assigned PN code between the base unit 10 and the remote unit 40 will result in communication between the other remote unit 40 and the base unit 10 at the same slot time. It does not interfere with communication (because these PN codes are different).

The frequency spectrum (902-9) selected for the interference operation
(28 MHz) is susceptible to interference from other RF sources, such as microwave devices, so that the communication link between the base unit 10 and one or more remote units 40 is likely to be disrupted. However, as described above, communication between the base unit 10 and all of its remote units 40 occurs on a single selected frequency channel. Thus,
If base unit 10 detects excessive interference in signals from one or more remote units 40, base unit 10 sends a signaling message in the DATA section of its USC-B portion to each of these remote units 40. To another frequency channel. This signaling message contains synchronization or clock information about the switching time. Upon receiving to each of the remote units 40 in this manner, the PCU 52 generates a frequency select signal to move to a new selected frequency channel.

Loss of Communication Link The mechanism described above causes communication to move from one frequency channel to another to avoid interference and maintain continuity of the communication link, but to an unexpectedly large amount. The communication link between the base unit 10 and one or more remote units 40 may be affected by interference signals or the like. In such a case, it will be necessary to establish a technique for re-establishing the communication link between the base unit 10 and one or more remote units 40 thereof.

As part of setting up such a communication link, the base unit 10 communicates with each of the remote units 40 before the base unit 10 and the remote unit 40 communicate in the UBC-B and UBC-R units, respectively. To transmit a communication channel table to be used in the case of communication interruption. That is, the table of this channel is transmitted from the base unit 10 to the UBC-B DATA.
It is communicated to the remote unit 40 via the unit. Further, the channel table consists of a list containing both frequency channels and PN code indexes.

The channel table is, for example, 0
Selected PN such as PN code index not equal to
Coded according to the code index. In addition, the table of channels is transmitted by the base unit 10 as if it were another part of "data". Also, the remote unit 40 receiving the channel table decodes the channel table according to the assigned PN code. After that, the decoded channel table signal is stored in the storage unit of the protocol and control unit 52.

If the communication is interrupted, the remote unit 40 operates to continue counting the clock signal based on the system clock 35 generated internally to the SSU 34. That is, the system clock 35
Continue counting based on synchronization in the continuation of the SYNC signal transmitted from the base unit 10. The protocol and control unit 52 then receives a timing signal from the system clock 35. That is, the protocol and control unit 52, which is a microcontroller, applies a predetermined mathematical function to this clock signal value. An example of a mathematical function used by such a remote unit 40 is a hash (ha)
sh) There is a function H (T). That is, the hash function H
(T) is a frame number T obtained from the clock signal.
To the program number H (T). A preferred embodiment of such a hash function H (T) is defined as follows.

H (T) = [R (T) × B] In this equation, [...] is a floor function, and R (T) = (((T / 8) × 7) +
3) mod16) / 16, which is a pseudo-random value in the area (0, 1).

Further, B is the entry number in the channel table. That is, R (T) adopts the above-mentioned minus-per-frame number T / 8 as a seed corresponding to the maximum number of 16 sequence-generating components, multiplies it by 7, then adds 3, and further adds a region ( It is obtained by normalizing to obtain the pseudo-random value in (0, 1).

Thus, the application of the mathematical function by the remote unit 40 to the clock signal value causes the entry in the channel table to be completed. Thereafter, the protocol and control unit 52 selects the communication channel associated with the selected entry in the table. As described above, the entry in the table of the selected communication channel includes the associated frequency channel and PN code index.

On the other hand, during this time, the base unit 10 continues to generate the clock signal by the system clock 35 attached thereto. Thus, the above-described protocol and control unit 32 applies the same mathematical function to the same value as the clock signal from the system clock 35 to obtain the same entry in the communication channel table. The base unit 10 then selects the communication channel associated with the entry in the table.
As a result, the communication process is reset on the communication channel selected from the entry in the communication channel table.

As part of the initial protocol between the capability setting base unit 10 and one or more remote units 40, when the remote unit 40 locks onto the SYNC signal in the CSC-B portion of the time slot, the unit 40 will Send the request signaling message in the CS-R part in CSC-R.
Thereafter, base unit 10 transmits, within the DATA portion of its CSC-B time slot, the index of the particular PN code used by remote unit 40 in the process of communicating with base unit 10.

[0171] The remote unit 40 decodes this and uses the selected PN code to send a list of its functional capabilities to the base unit 10. Thus, remote unit 40 sends on time slot USC-R a list of functional capabilities encoded by the selected PN code, eg, PN code = 10.

Thereafter, the base unit 10 is connected to the USC-R
Receives a message in the time slot, decodes this signal according to the selected PN code, and
Get a list of functional capabilities of. The base unit then compares the list of functional capabilities of the remote unit 40 with its functional capabilities to determine a common functional capability combination. Thereafter, the base unit 10 is connected to the remote unit 4.
For 0, send a list of the common functional capability combination encoded according to the selected PN code on the DATA portion of the USC-B time slot. In this way, communication between the remote unit 40 and the base unit 10 takes place at the selected frequency using a combination of common functional capabilities according to the selected PN code.

Remote unit 40 and base unit 1
Zero functional capabilities may include capabilities such as speech digital encoding. In this case, different speech coding techniques (some based on generally known principles and others based on the proprietary principles of a particular manufacturer) are effective, and at least remote units 40 from different manufacturers are required. In order to have the ability to communicate with the base unit 10 from different manufacturers based on common functional capabilities,
As part of setting up the communication link, it is desirable that the remote unit 40 and the base unit 10 know a common functional capability.

An example of the functional capability corresponding to the conversation code in the base unit 10 and the remote unit 40 will be described below.

Base Unit 10 Remote Unit 40 Enhanced Sub-Band Sub-Band CELP Proprietary As can be seen from the list of functional capabilities by the remote unit 40, the base unit 10 compares the above table and adds 16Kbps to the corresponding list of common capabilities. Determine that subbands and 32 Kbps ADPCM are included. Based on this comparison, base unit 10 sends the list of functional capabilities as described above to remote unit 40, and communication is performed using either of the two functional capabilities corresponding to the speech code.

Thus, since the remote unit 40 and the base unit 10 have the ability to "negotiate" a common list of capabilities, they have exclusive rights in the conversation coding of the base unit 10 or the remote unit 40. Some manufacturers can communicate with other manufacturers' remote units 40 or base units 10 as long as there is a common element in at least one of the conversational coding capabilities of both units of these manufacturers. It is.

[0177] The power control base unit 10 is capable of communicating with a plurality of remote units 40, wherein the units 10 are controlled for the transmit power of each remote unit 40 and the remote units received by the base unit 10. The signal strength from each of the remote units 40 is approximately the same.
It is desirable that any one of them does not overpower or control another unit. further,
Such power control is preferable in terms of suppressing multipath fading and shielding distortion.

In the communication system 8, the signal transmitted by the base unit 10 is transmitted to the remote unit 40.
And the power of the signal received from the base unit 10 is measured by the detector 104 of the BPU 28 a in the remote unit 40. Then, the remote unit 4
The transmission power at 0 is controlled according to the following equation:

Power = A + (BC) where A denotes the desired power received by base unit 10 in the signal transmitted by remote unit 40.

B indicates the power of the signal transmitted by the base unit 10, and C indicates the power of the signal received by the remote unit 40 measured by the detector 104 of the baseband processing unit 28a. . The values of A and B are data transmitted from the base unit 10 to the remote unit 40 to control the transmission power of the remote unit 40. Further, A is the desired power received by base unit 10 of the signal transmitted by remote unit 40 measured by detector 104 of base unit 10. This value is transmitted from the base unit 10 to the remote unit 40 by the USC-B
Is a value transmitted on the DATA section. B is the power of the signal transmitted by the base unit 10, which is also a value transmitted from the base unit 10 to the remote unit 40 on the DATA section of its USC-B. Thus, A and B are known a priori to remote unit 40 or are part of a signaling message sent from base unit 10 to remote unit 40.

Also, the gain control signal generated by the protocol and control unit 52 in the remote unit 40 controls the gain of the RF filter and amplifier 90 which affects the power of the transmitted signal. The gain controlled RF amplifier 90 is a Motorola (Motorol).
A well-known configuration such as a part AN1025 manufactured by a) can be adopted.

Data Coding As described above, the UC-B section and the UC-R section are composed of the USC and UBC sections. Therefore, UC
In the -B time slot, signals USC-B and U
BC-B is transmitted, and USC-B is a control signal portion including information such as power activation and paging state, and UBC-B
Is the part containing the data. Similarly, in the UC-R portion, the UC-R is composed of the PA2 and the USC-R portions, and these are control signals using the UBC-R as a data portion.

The control signal portion of these UC-B and UC-R is a digital data stream having a smaller amount of digital data than the data portion of UC-B and UC-R. The control signal and data portions of both UC-B and UC-R can be further digitally encoded to protect the control signal portion to further enhance its interference immunity.

The encoding of such digital data is performed as follows. That is, from the data portion, each N-bit block is a specific “light” (here, “light”
t) "means that the number of 1's is less than the number of 0's) mapped to an M-bit signal, where M is greater than N and M
The number of “1” s in the bit signal is smaller than M / 2.
This light M-bit signal is transmitted when the bit from the control signal part of UC-B or UC-R is "0", but the bit from the control signal part of UC-B or UC-R is "1". , A light M-bit signal complement is transmitted.

Although channel coding is widespread in modern communication systems, such channel codes simply add redundancy to the information stream that produces the coded bit stream in transmissions on noisy channels. Things. If such a channel code is suitably created, the decoder will reliably recover the original information flow even if some of the transmitted bits fail due to the redundancy induced by this coding. be able to.

In the device according to the invention, the purpose of the coding is to provide maximum protection against transmission errors in the control signal part of the UC-B or UC-R time slot mentioned above, and The goal is to provide minimal protection in the data portion of the UC-R. In this way, the received unit (remote unit 40
Alternatively, the base unit 10) can recover both the control signal and the data signal under a low error rate condition, and can recover the control signal under a very high error rate condition. Become.

An example of the above-mentioned coding technique will be described below with reference to the drawings. First, a single bit of the control signal and 96 bits of data are coded into a coded bit stream having 120 bits for transmission. 96 bit words to 120
Mapping to bit words is performed by dividing a 96-bit word into three sets of 32-bit words. The 32-bit words are then mapped to light 40-bit words each. Further, these three 40-bit words are concatenated to form a light 120-bit word.

[0188] Mathematically _{speaking, 2 32} C (40,1
Since it is smaller than the combination of 2), the 32-bit sequence has a Hamming weight of 4 which definitely contains 12 or 12 1s.
It can be mapped to a sequence of 0 bits.

That is, the three types of 40-bit words mapped from the three types of 32-bit input words from the data channel are concatenated to form a 120-bit word of the Hamming weight 36. In this case, if a single bit from the control signal is 0, a 120-bit word is sent. Also, if the single bit from the control signal is one, the complement of a 120-bit word is sent out and its weight is 120-36 = 8
It consists of 4 bits “1”.

The difference between the weights is 84-36 = 48, and more than 24 out of 120 bits will have an error before a "light" M-bit word is mistaken for a "heavy" M-bit word or vice versa. It means becoming.

In such an example, there is the disadvantage that any channel error causes the loss of one 32-bit portion in the encoded data. This problem can be improved by adding a normal single stream (127, 120) Hamming code. That is, adding seven cyclic redundancy check (CRC) bits to a 120-bit word allows for the correction of any single-bit errors in the 127-bit block. By making such an improvement, even if a signal smaller than 2 bits changes due to noise, the decoding process can produce correct results in both the control signal and the data signal.

[Brief description of the drawings]

FIG. 1 is a block diagram of a base unit according to the present invention.

FIG. 2 is a block diagram of the remote unit of the present invention.

FIG. 3 shows the RF / I of the base unit shown in FIG. 1;
It is a detailed block diagram of F analog part.

FIG. 4 is an RF / IF of the remote unit shown in FIG.
It is a detailed block diagram of an analog part.

FIGS. 5a to 5c are parts of a block diagram of the standby and synchronization units of the base unit shown in FIG. 1 and the remote unit shown in FIG. 2, respectively.

FIG. 6 shows the base unit shown in FIG.
FIG. 4 is a detailed block diagram of the interface and multiplexer portions of the illustrated remote unit.

FIG. 7 shows the base unit and the second unit shown in FIG.
FIG. 3 is a detailed block diagram of the application controller portion of the illustrated remote unit.

FIG. 8 is a schematic diagram of the frequency spectrum, in which the preferred embodiment of the communication system of the present invention operates in the region shown in FIG.

FIG. 9 is a timing diagram in a communication protocol between a base unit and a remote unit.

FIG. 10 is a detailed timing diagram of FIG. 9, showing the parts transmitted by the base unit.

FIG. 11 is a detailed timing diagram of FIG. 9, showing the parts transmitted by the remote unit.

Continued on the front page (31) Priority claim number 789,737 (32) Priority date November 8, 1991 (1991.11.8) (33) Priority claim country United States (US) (31) Priority claim No. 789,292 (32) Priority date November 8, 1991 (1991.11.18) (33) Priority claiming country United States (US) (31) Priority claim number 789,736 (32) Priority date Heisei Nov. 8, 1991 (November 18, 1991) (33) Priority Country United States (US) (72) Keith Jarrett United States 94611 Oakland Villanova Drive, California 94611 California 20 (72) David Messerschmit United States 94556 Lamp Court, Moraga, California 4 (72) Inventor Christopher Floors United States 94611 Auckland, California Fairmount Avenue 621 (72) Inventor Huifen Lu United States 94506 Danville Silver Maple Drive, California 3478 (72) Inventor Chun-Men Sue United States 94549 Lafayette Apartments, 204 East Street 949 (72) Inventor Saman Bettash United States 94708 Berkeley Scenic Avenue, California 1537 (72) Inventor Edward Chen United States 94539 Fremont, California Mission Ridge Coat 48 F Term (Reference) 5K022 EE02 EE21 EE31 5K067 CC10 DD44 EE02 EE10 EE22 GG08 GG09 HH21

Claims (12)

[Claims] 1. A method for controlling the power of a remote transmission signal transmitted to a base communication device on a predetermined frequency channel at a predetermined first time by a remote communication device, the method comprising: A device transmitting a base transmission signal on the frequency channel to the remote device at a predetermined second time different from the first time, and further receiving the base transmission signal on the frequency channel by the remote device; Measuring the power of the base transmit signal received by the remote device; and controlling the transmit power of the remote transmit signal on the frequency channel according to the equation: power = A + (BC). A indicates the desired power of the remote transmission signal received by the base device; Wherein indicates the power of the base transmission signal, method characterized in that C indicates the measured power of the base transmission signal when received by the remote device. 2. The method of claim 1, wherein said parameters A and B are transmitted by said base communication device to said remote communication device. 3. An apparatus for controlling the power of a remote transmission signal transmitted to a base communication apparatus in a predetermined frequency channel at a predetermined first time by a remote communication apparatus in an open-loop manner, wherein the base apparatus includes: The first
Transmitting a base transmission signal to the remote device on the frequency channel at a predetermined second time different from the time;
Means for receiving the base transmission signal on the frequency channel by the remote device; means for measuring the power of the base transmission signal received by the remote device; and power = A + (BC). Means for controlling the transmit power of the remote transmit signal on the frequency channel, wherein A indicates the desired power of the remote transmit signal received by the base device, B indicates the power of the base transmit signal, C Indicates the measured power of the base transmit signal as received by the remote device. 4. A means for transmitting a remote transmission signal to a base unit using CDMA within a predetermined time on a selected frequency channel, and transmitting the remote transmission signal on the selected frequency channel within another time different from the predetermined time. Means for receiving the base transmission signal from the base unit using CDMA; means for measuring the power of the base transmission signal; and means for calculating the transmission power of the remote transmission signal according to the equation: power = A + (BC). Means for controlling; A indicating the desired power of the remote transmission signal received by the base device; B indicating the power of the base transmission signal; and C indicating the base transmission signal when received by the remote device. Characterized by indicating the measured power of
Remote unit for wireless communication with the base unit. 5. The transmission means further comprising means for transmitting a control signal during a portion of the predetermined time and transmitting a CDMA coded data signal during another portion of the predetermined time. The remote unit according to claim 4. 6. The remote unit according to claim 4, wherein said receiving means further receives a synchronization signal from said base unit. 7. The reception means further comprises: means for detecting the base transmission signal; and means for decoding the base transmission signal using CDMA to generate a decoded base transmission signal. The remote unit according to claim 4. 8. A method according to claim 1, wherein said transmitting means transmits a first control signal and a first data signal within said predetermined time, and said receiving means receives a second control signal and a second data signal within another time. The remote unit according to claim 4, characterized in that: 9. The remote unit according to claim 8, wherein the remote unit can take one of three states: an off state, a standby state, and an on state. 10. The apparatus according to claim 9, wherein when the remote unit is in a standby state, the remote unit transmits only the first control signal and receives only the synchronization signal and the second control signal. Remote unit. 11. The remote unit according to claim 4, wherein said selected frequency channel is selected as one of a plurality of frequency channels. 12. The remote unit according to claim 11, further comprising means for changing transmission to another frequency channel to change to another frequency in response to a request from said base unit. .