# US 5,710,546 A · Apparatus for encoding and decoding a digital radio signal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,710,546 A - Document ID: US5710546A - Status: Granted - Kind: A - Application number: 08/552,644 - Filed: 1995-11-03 - Granted: 1998-01-20 - Earliest claimed: 1994-05-04 - Assignees: Motorola, Inc. - Inventors: Clifford Dana Leitch - Web page: https://patentgrep.com/patent/US5710546A ## CPC - H04H 20/67: Common-wave systems, i.e. using separate transmitters operating on substantially the same frequency - H03M 13/2703: {the interleaver involving at least two directions} - H04W 88/187: {using digital or pulse address codes} - H04H: BROADCAST COMMUNICATION (multiplex communication H04J; pictorial communication aspects of broadcast systems H04N) - H03M: CODING; DECODING; CODE CONVERSION IN GENERAL (using fluidic means F15C4/00; optical analogue/digital converters G02F7/00; coding, decoding or code conversion, specially adapted for particular applications, see the relevant subclasses, e.g. G01D, G01R, G06F, G06T, G09G, G10L, G11B, G11C, H04B, H04L, H04M, H04N; ciphering or deciphering for cryptography or other purposes involving the need for secrecy G09C) - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) ## Abstract A radio communication system (100) includes a system controller (102) for encoding data information to generate data messages which have periodic error protection at one or more burst error frequencies. The system controller (102) transmits one or more of the data messages to at least two transmitters (103) for simultaneous transmission of the one or more data messages. The first and second transmitters (103) have radio carrier frequencies which are offset by an offset frequency which is substantially equivalent to one of the one or more burst error frequencies. A selective call receiver (106) receives and decodes a radio signal including a data message having periodic burst errors at the offset frequency and wherein the data message includes encoding which provides substantial periodic burst error protection at the offset frequency. ## Claims ### Claim 1 A radio communication system having two or more transmitters for transmitting data messages intended for at least one selective call receiver using radio signals, comprising: a system controller for encoding data information to generate the data messages which have periodic error protection at one or more burst error frequencies, wherein the system controller transmits one or more of the data messages to at least two transmitters for simultaneous transmission of one or more of the data messages; a first transmitter having a first radio carrier frequency for transmitting a first of the one or more data messages; and a second transmitter for simultaneously transmitting a second of the one or more data messages, wherein said second transmitter has a second radio carrier frequency which is offset from the first radio carrier frequency by an offset frequency substantially equivalent to one of the one or more burst error frequencies. ### Claim 2 (depends on 1) The radio communication system according to claim 1, wherein the system controller is for encoding data information using a multidimensional code which generates data messages having periodic burst error protection at at least two burst error frequencies. ### Claim 3 (depends on 2) The radio communication system according to claim 2, wherein the radio communication system has at least three transmitters and at least three offset frequencies which are determined by differences of carrier frequencies of pairs of said at least three transmitters, and the multidimensional code is a three dimensional code which generates data messages having periodic burst error protection at the at least three offset frequencies. ### Claim 4 (depends on 3) The radio communication system according to claim 3, wherein the three dimensional code has parity protection used in only two dimensions. ### Claim 5 (depends on 2) The radio communication system according to claim 2, wherein the multidimensional code has error protection symbols in all but one dimension. ### Claim 6 (depends on 1) The radio communication system according to claim 1, wherein the second of the one or more data messages is the same as the first of the one or more data messages and is transmitted by said first and second transmitters in a simulcast mode. ### Claim 7 (depends on 1) The radio communication system according to claim 1, wherein the second of the one or more data messages is the same as the first of the one or more data messages and the first and second data messages are transmitted by said first and second transmitters in a reuse mode. ### Claim 8 (depends on 1) The radio communication system according to claim 1, further comprising at least one selective call radio which receives and decodes a radio signal including one of the one or more data messages which has periodic burst errors at the offset frequency and wherein the one of the one or more data messages includes encoding which provides substantial periodic error protection at one or more burst frequencies including one burst frequency substantially equivalent to the offset frequency. ### Claim 9 A selective call radio, for use in a radio communication system having a plurality of transmitters, said selective call radio comprising: a receiver for receiving a radio signal including a data message having periodic burst errors induced at an offset frequency which is a difference of carrier frequencies of two of the plurality of transmitters; and a processor for decoding the data message, wherein the data message has substantial periodic burst error protection at a frequency substantially equivalent to the offset frequency. ### Claim 10 (depends on 9) The selective call radio according to claim 9, wherein the data message received by said receiver has periodic burst errors induced by two or more offset frequencies which are differences of carrier frequencies of at least three of the plurality of transmitters, and wherein the data message decoded by said processor has multidimensional encoding which provides substantial periodic burst error protection at frequencies substantially equivalent to the two or more offset frequencies. ### Claim 11 (depends on 10) The selective call radio according to claim 10, wherein the data message includes multidimensional encoding which is three dimensional encoding. ### Claim 12 (depends on 11) The selective call radio according to claim 11, wherein the three dimensional encoding includes parity protection used in only two dimensions. ### Claim 13 (depends on 10) The radio communication system according to claim 10, wherein the multidimensional encoding includes error protection symbols in all but one dimension.