METHOD FOR PROCESSING THE RANDOM ACCESS TRANSMISSION IN THE FREQUENCY DOMAIN

• US 20090225707A1
• Filed: 01/24/2007
• Published: 09/10/2009
• Est. Priority Date: 02/03/2006
• Status: Active Grant

• Current Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Original Assignee: Unwired Planet LLC (JP Morgan Chase & Co)
• Inventors: Peters, Gunnar, Haartsen, Jacobus Cornelis, Parkvall, Stefan, Sahlin, Henrik, Baldemair, Robert
• Granted Patent: US 8,391,131 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04J 13/0003 Code application, i.e. aspects relating to how codes are applied to form multiplexed channels
• CPC Class Codes: H04L 27/2607 Cyclic extensions
• CPC Class Codes: H04L 27/2613 Structure of the reference signals
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access

Abstract

There is provided a method of operating a communication system, the communication system comprising a user equipment and a receiver, the method in the system comprising generating a random access transmission in a user equipment and transmitting the random access transmission to the receiver in the communication system, the random access transmission including a preamble; receiving the random access transmission from the user equipment at the receiver; processing the random access transmission in the frequency domain to detect the preamble. In preferred embodiments of the invention, the preamble has a cyclic prefix, or is preceded by a plurality of zero-valued symbols.

Claims

1. A method of operating a communication system, the communication system comprising a user equipment and a receiver, the method in the system comprising:

generating a random access transmission in a user equipment and transmitting the random access transmission to the receiver in the communication system, the random access transmission including a preamble,

receiving the random access transmission from the user equipment at the receiver;

processing the random access transmission in the frequency domain to detect the preamble.

2. A method as claimed in claim 1, wherein the step of generating the random access transmission comprises generating the preamble with a first cyclic prefix.

3. A method as claimed in claim 2, wherein the first cyclic prefix has a length that is at least equal to the maximum round trip delay for signals between the user equipment and the receiver.

4. A method as claimed in claim 2, wherein the first cyclic prefix has a length that is at least equal to the maximum round trip delay for signals between the user equipment and the receiver plus the maximum delay spread of the channel between the user equipment and the receiver.

5. A method as claimed in claim 2, 3 or 4, wherein the step of generating comprises generating a random access transmission in which the trail of the preamble comprises a known training sequence.

6. A method as claimed in claim 5, wherein the step of generating comprises generating a random access transmission in which at least a portion of the first cyclic prefix comprises a repeat of the known training sequence.

7. A method as claimed in claim 2, 3, 4, 5 or 6, wherein the step of generating comprises generating a random access transmission which further comprises a message block.

8. A method as claimed in claim 7, wherein the step of generating comprises generating a random access transmission in which the message block has a second cyclic prefix.

9. A method as claimed in claim 8, wherein the second cyclic prefix is shorter than the first cyclic prefix.

10. A method as claimed in claim 9, wherein the second cyclic prefix has a length that is at least equal to the maximum delay spread of the channel between the user equipment and the receiver.

11. A method as claimed in claim 8, 9 or 10, wherein the step of generating comprises generating a random access transmission in which the message block ends with a known training sequence.

12. A method as claimed in claim 11, wherein the length of the second cyclic prefix is such that the second cyclic prefix preceding the message block corresponds to the known training sequence.

13. A method as claimed in any of claims 8, 9, 10, 11 or 12, when dependent on claims 2, 3 or 4, wherein the second cyclic prefix before the message block is considered to be a part of the preamble, and thus forms a portion of the first cyclic prefix.

14. A method as claimed in claim 1, wherein the step of generating comprises generating a random access transmission in which the preamble is preceded by a first plurality of zero-valued symbols.

15. A method as claimed in claim 14, wherein the step of generating comprises generating a random access transmission in which the preamble is followed by a second plurality of zero-valued symbols.

16. A method as claimed in claim 14 or 15, wherein the step of generating comprises generating a random access transmission which further comprises a message block.

17. A method as claimed in claim 16, wherein the step of generating comprises generating a random access transmission in which the message block precedes the preamble.

18. A method as claimed in claim 17, wherein the step of generating comprises generating a random access transmission in which the message block is preceded by a third plurality of zero-valued symbols.

19. A method as claimed in claim 17, wherein the step of generating comprises generating a random access transmission in which the message block has a second cyclic prefix.

20. A method as claimed in claim 16, wherein the step of generating comprises generating a random access transmission in which the message block follows the preamble.

21. A method as claimed in claim 20, wherein the step of generating comprises generating a random access transmission in which the message block is followed by a third plurality of zero-valued symbols.

22. A method as claimed in any of claims 14 to 21, wherein the preamble has a length of N samples, and the step of processing comprises:

identifying an N-sample long portion of the received random access transmission to process, the N-sample long window covering at least a part of the preamble;

adding any part of the preamble falling outside the N-sample long portion to the start of the N-sample long portion.

23. A method as claimed in any of claims 2 to 22, wherein the step of processing the random access transmission comprises:

applying a Fourier transform to a portion of the received random access transmission.

24. A method as claimed in claim 23 when dependent on any of claims 2 to 13, wherein the step of applying a Fourier transform further comprises applying a respective Fourier transform to each of a plurality of portions of the received random access transmission.

25. A method as claimed in claim 24, wherein the plurality of portions of the received random access transmission partially overlap.

26. A method as claimed in claim 25, wherein the plurality of portions are offset from each other by an amount that corresponds to the difference between the length of the first cyclic prefix and the maximum delay spread of the radio channel over which the random access transmission was transmitted.

27. A method as claimed in claim 23, 24, 25 or 26, wherein the portion or portions have a length that is equal to the length of the preamble.

28. A method as claimed in any of claims 23 to 27, wherein the step of generating comprises selecting, by the user equipment, the preamble from a set of possible preambles, and the step of processing further comprises:

calculating a conjugate complex Fourier transform of each of the preambles in the set; and

multiplying each of the calculated Fourier transformed preambles by the result of the applying step.

29. A method as claimed in claim 28, wherein the step of processing further comprises:

calculating an inverse Fourier transform of each result from the multiplying step.

30. A method as claimed in claim 29, wherein the step of processing further comprises:

comparing the results of the calculating an inverse Fourier transform step with a threshold to determine which of the preambles was used in the random access transmission.

31. A method as claimed in any of claims 23 to 30, wherein the step of processing the random access transmission further comprises:

extracting the frequency band used to transmit the random access transmission from the Fourier transformed portion of the received random access transmission.

32. A method as claimed in any preceding claim, further comprising the step of determining a time difference between the user equipment and the receiver from the detected preamble.

33. A method as claimed in claim 32, wherein the time difference between the user equipment and the receiver comprises a delay introduced by the propagation of the signal from the user equipment to the receiver.

34. A method as claimed in any preceding claim, further comprising the step of determining a received power level at the receiver from the detected preamble.

35. A communication system comprising:

a user equipment adapted to generate a random access transmission including a preamble, and to transmit the random access transmission to a receiver in the communication system; and

a receiver adapted to receive the random access transmission from the user equipment and to process the random access transmission in the frequency domain to detect the preamble.

36. A system as claimed in claim 35, wherein the user equipment is adapted to generate a random access transmission in which the preamble has a first cyclic prefix.

37. A system as claimed in claim 36, wherein the first cyclic prefix has a length that is at least equal to the maximum round trip delay for signals between the user equipment and the receiver.

38. A system as claimed in claim 36, wherein the first cyclic prefix has a length that is at least equal to the maximum round trip delay for signals between the user equipment and the receiver plus the maximum delay spread of the channel between the user equipment and the receiver.

39. A system as claimed in claim 36, 37 or 38, wherein the user equipment is adapted to generate a random access transmission in which the trail of the preamble comprises a known training sequence.

40. A system as claimed in claim 39, wherein the user equipment is adapted to generate a random access transmission in which at least a portion of the first cyclic prefix comprises a repeat of the known training sequence.

41. A system as claimed in any of claims 36 to 40, wherein the user equipment is adapted to generate a random access transmission which further comprises a message block.

42. A system as claimed in claim 41, wherein the user equipment is adapted to generate a random access transmission in which the message block has a second cyclic prefix.

43. A system as claimed in claim 42, wherein the second cyclic prefix is shorter than the first cyclic prefix.

44. A system as claimed in claim 43, wherein the second cyclic prefix has a length that is at least equal to the maximum delay spread of the channel between the user equipment and the receiver.

45. A system as claimed in claim 42, 43 or 44, wherein the user equipment is adapted to generate a random access transmission in which the message block ends with a known training sequence.

46. A system as claimed in claim 45, wherein the length of the second cyclic prefix is such that the second cyclic prefix preceding the message block corresponds to the known training sequence.

47. A system as claimed in any of claims 42, 43, 44, 45 or 46, when dependent on claims 36, 37 or 38, wherein the second cyclic prefix before the message block is considered to be a part of the preamble, and thus forms a portion of the first cyclic prefix.

48. A system as claimed in claim 35, wherein the user equipment is adapted to generate a random access transmission in which the preamble is preceded by a first plurality of zero-valued symbols.

49. A system as claimed in claim 48, wherein the user equipment is adapted to generate a random access transmission in which the preamble is followed by a second plurality of zero-valued symbols.

50. A system as claimed in claim 48 or 49, wherein the user equipment is adapted to generate a random access transmission which further comprises a message block.

51. A system as claimed in claim 50, wherein the user equipment is adapted to generate a random access transmission in which the message block precedes the preamble.

52. A system as claimed in claim 51, wherein the user equipment is adapted to generate a random access transmission in which the message block is preceded by a third plurality of zero-valued symbols.

53. A system as claimed in claim 51, wherein the user equipment is adapted to generate a random access transmission in which the message block has a second cyclic prefix.

54. A system as claimed in claim 50, wherein the user equipment is adapted to generate a random access transmission in which the message block follows the preamble.

55. A system as claimed in claim 54, wherein the user equipment is adapted to generate a random access transmission in which the message block is followed by a third plurality of zero-valued symbols.

56. A system as claimed in any of claims 48 to 55, wherein the preamble has a length of N samples, and the receiver is adapted to process the random access transmission by identifying an N-sample long portion of the received random access transmission to process, the N-sample long window covering at least a part of the preamble, and adding any part of the preamble falling outside the N-sample long portion to the start of the N-sample long portion.

57. A system as claimed in any of claims 36 to 56, wherein the receiver is adapted to process the random access transmission by applying a Fourier transform to a portion of the received random access transmission.

58. A system as claimed in claim 57 when dependent on any of claims 36 to 47, wherein the receiver is adapted to process the random access transmission by applying a respective Fourier transform to each of a plurality of portions of the received random access transmission.

59. A system as claimed in claim 58, wherein the plurality of portions of the received random access transmission partially overlap.

60. A system as claimed in claim 59, wherein the plurality of portions are offset from each other by an amount that corresponds to the difference between the length of the first cyclic prefix and the maximum delay spread of the radio channel over which the random access transmission was transmitted.

61. A system as claimed in claim 57, 58, 59 or 60, wherein the portion or portions have a length that is equal to the length of the preamble.

62. A system as claimed in any of claims 57 to 61, wherein the user equipment is adapted to generate the random access transmission by selecting the preamble from a set of possible preambles, and the receiver is adapted to process the random access transmission by calculating a conjugate complex Fourier transform of each of the preambles in the set;

and multiplying each of the calculated Fourier transformed preambles by the Fourier transformed portion or portions.

63. A system as claimed in claim 62, wherein the receiver is adapted to process the random access transmission by calculating an inverse Fourier transform of each multiplication.

64. A system as claimed in claim 63, wherein the receiver is adapted to process the random access transmission by comparing the results of the calculating an inverse Fourier transform step with a threshold to determine which of the preambles was used in the random access transmission.

65. A system as claimed in any of claims 57 to 64, wherein the receiver is adapted to process the random access transmission by extracting the frequency band used to transmit the random access transmission from the Fourier transformed portion of the received random access transmission.

66. A system as claimed in any of claims 35 to 65, the receiver being further adapted to determine a time difference between the user equipment and the receiver from the detected preamble.

67. A system as claimed in claim 66, wherein the time difference between the user equipment and the receiver comprises a delay introduced by the propagation of the signal from the user equipment to the receiver.

68. A system as claimed in any of claims 35 to 67, the receiver being further adapted to determine a received power level at the receiver from the detected preamble.

69. A method of operating a device in a communication system, the method comprising:

generating a random access transmission including a preamble, the random access transmission being suitable for processing by a receiver in the communication system in the frequency domain; and

transmitting the random access transmission to a receiver in the communication system.

70. A method as claimed in claim 69, wherein the step of generating the random access transmission comprises generating the preamble with a first cyclic prefix.

71. A method as claimed in claim 70, wherein the first cyclic prefix has a length that is at least equal to the maximum round trip delay for signals between the device and the receiver.

72. A method as claimed in claim 70, wherein the first cyclic prefix has a length that is at least equal to the maximum round trip delay for signals between the device and the receiver plus the maximum delay spread of the channel between the device and the receiver.

73. A method as claimed in claim 70, 71 or 72, wherein the step of generating comprises generating a random access transmission in which the trail of the preamble comprises a known training sequence.

74. A method as claimed in claim 73, wherein the step of generating comprises generating a random access transmission in which at least a portion of the first cyclic prefix comprises a repeat of the known training sequence.

75. A method as claimed in claim 70, 71, 72, 73 or 74, wherein the step of generating comprises generating a random access transmission which further comprises a message block.

76. A method as claimed in claim 75, wherein the step of generating comprises generating a random access transmission in which the message block has a second cyclic prefix.

77. A method as claimed in claim 76, wherein the second cyclic prefix is shorter than the first cyclic prefix.

78. A method as claimed in claim 77, wherein the second cyclic prefix has a length that is at least equal to the maximum delay spread of the channel between the user equipment and the receiver.

79. A method as claimed in claim 76, 77 or 78, wherein the step of generating comprises generating a random access transmission in which the message block ends with a known training sequence.

80. A method as claimed in claim 79, wherein the length of the second cyclic prefix is such that the second cyclic prefix preceding the message block corresponds to the known training sequence.

81. A method as claimed in any of claims 76 to 80, when dependent on claims 70, 71 or 72, wherein the second cyclic prefix before the message block is considered to be a part of the preamble, and thus forms a portion of the first cyclic prefix.

82. A method as claimed in claim 69, wherein the step of generating comprises generating a random access transmission in which the preamble is preceded by a first plurality of zero-valued symbols.

83. A method as claimed in claim 82, wherein the step of generating comprises generating a random access transmission in which the preamble is followed by a second plurality of zero-valued symbols.

84. A method as claimed in claim 82 or 83, wherein the step of generating comprises generating a random access transmission which further comprises a message block.

85. A method as claimed in claim 84, wherein the step of generating comprises generating a random access transmission in which the message block precedes the preamble.

86. A method as claimed in claim 85, wherein the step of generating comprises generating a random access transmission in which the message block is preceded by a third plurality of zero-valued symbols.

87. A method as claimed in claim 85, wherein the step of generating comprises generating a random access transmission in which the message block has a second cyclic prefix.

88. A method as claimed in claim 84, wherein the step of generating comprises generating a random access transmission in which the message block follows the preamble.

89. A method as claimed in claim 88, wherein the step of generating comprises generating a random access transmission in which the message block is followed by a third plurality of zero-valued symbols.

90. A device for use in a communication system, the device comprising:

transmit means for generating and transmitting a random access transmission to a receiver in order to access the communication system, the random access transmission comprising a preamble, the random access transmission being suitable for processing by the receiver in the frequency domain.

91. A device as claimed in claim 90, wherein the transmit means are adapted to generate a random access transmission in which the preamble has a first cyclic prefix.

92. A device as claimed in claim 91, wherein the first cyclic prefix has a length that is at least equal to the maximum round trip delay for signals between the device and the receiver.

93. A device as claimed in claim 91, wherein the first cyclic prefix has a length that is at least equal to the maximum round trip delay for signals between the device and the receiver plus the maximum delay spread of the channel between the device and the receiver.

94. A device as claimed in claim 91, 92 or 93, wherein the transmit means are adapted to generate a random access transmission in which the trail of the preamble comprises a known training sequence.

95. A device as claimed in claim 94, wherein the transmit means are adapted to generate a random access transmission in which at least a portion of the first cyclic prefix comprises a repeat of the known training sequence.

96. A device as claimed in any of claims 91 to 95, wherein the transmit means are adapted to generate a random access transmission which further comprises a message block.

97. A device as claimed in claim 96, wherein the transmit means are adapted to generate a random access transmission in which the message block has a second cyclic prefix.

98. A device as claimed in claim 97, wherein the second cyclic prefix is shorter than the first cyclic prefix.

99. A device as claimed in claim 98, wherein the second cyclic prefix has a length that is at least equal to the maximum delay spread of the channel between the device and the receiver.

100. A device as claimed in claim 97, 98 or 99, wherein the transmit means are adapted to generate a random access transmission in which the message block ends with a known training sequence.

101. A device as claimed in claim 100, wherein the length of the second cyclic prefix is such that the second cyclic prefix preceding the message block corresponds to the known training sequence.

102. A device as claimed in any of claims 97 to 101 when dependent on claims 91, 92 or 93, wherein the second cyclic prefix before the message block is considered to be a part of the preamble, and thus forms a portion of the first cyclic prefix.

103. A device as claimed in claim 90, wherein the transmit means are adapted to generate a random access transmission in which the preamble is preceded by a first plurality of zero-valued symbols.

104. A device as claimed in claim 103, wherein the transmit means are adapted to generate a random access transmission in which the preamble is followed by a second plurality of zero-valued symbols.

105. A device as claimed in claim 103 or 104, wherein the transmit means are adapted to generate a random access transmission which further comprises a message block.

106. A device as claimed in claim 105, wherein the transmit means are adapted to generate a random access transmission in which the message block precedes the preamble.

107. A device as claimed in claim 106, wherein the transmit means are adapted to generate a random access transmission in which the message block is preceded by a third plurality of zero-valued symbols.

108. A device as claimed in claim 106, wherein the transmit means are adapted to generate a random access transmission in which the message block has a second cyclic prefix.

109. A device as claimed in claim 105, wherein the transmit means are adapted to generate a random access transmission in which the message block follows the preamble.

110. A device as claimed in claim 109, wherein the transmit means are adapted to generate a random access transmission in which the message block is followed by a third plurality of zero-valued symbols.

111. A device as claimed in any of claims 90 to 110, wherein the device is a user equipment.

112. A method of operating a receiver in a communication system, the method comprising:

receiving a random access transmission from a user equipment, the random access transmission including a preamble, the random access transmission being formed to allow processing in the frequency domain;

processing the random access transmission in the frequency domain to detect the preamble.

113. A method as claimed in claim 112, wherein the step of receiving comprises receiving a random access transmission in which the preamble has a first cyclic prefix.

114. A method as claimed in claim 112, wherein the step of receiving comprises receiving a random access transmission in which the preamble is preceded by a first plurality of zero-valued symbols.

115. A method as claimed in claim 114, wherein the step of receiving comprises receiving a random access transmission in which the preamble is followed by a second plurality of zero-valued symbols.

116. A method as claimed in either of claims 114 or 115, wherein the preamble has a length of N samples, and the step of processing comprises identifying an N-sample long portion of the received random access transmission to process, the N-sample long window covering at least a part of the preamble;

and adding any part of the preamble falling outside the N-sample long portion to the start of the N-sample long portion.

117. A method as claimed in any of claims 113, 114, 115 or 116, wherein the step of processing comprises applying a Fourier transform to a portion of the received random access transmission.

118. A method as claimed in claim 117 when dependent on claim 113, wherein the step of processing comprises applying a respective Fourier transform to each of a plurality of portions of the received random access transmission.

119. A method as claimed in claim 118, wherein the plurality of portions of the received random access transmission partially overlap.

120. A method as claimed in claim 119, wherein the plurality of portions are offset from each other by an amount that corresponds to the difference between the length of the first cyclic prefix and the maximum delay spread of the radio channel over which the random access transmission was transmitted.

121. A method as claimed in claim 117, 118, 119 or 120, wherein the portion or portions have a length that is equal to the length of the preamble.

122. A method as claimed in any of claims 117 to 121, wherein the step of processing is comprises calculating a conjugate complex Fourier transform of each of a plurality of preambles in a set of possible preambles;

and multiplying each of the calculated Fourier transformed preambles by the result of the applying step.

123. A method as claimed in claim 122, wherein the step of processing comprises calculating an inverse Fourier transform of each result from the multiplying step.

124. A method as claimed in claim 123, wherein the step of processing comprises comparing the results of the calculating an inverse Fourier transform step with a threshold to determine which of the preambles was used in the random access transmission.

125. A method as claimed in any of claims 117 to 124, wherein the step of processing comprises extracting the frequency band used to transmit the random access transmission from the Fourier transformed portion of the received random access transmission.

126. A method as claimed in any of claims 112 to 125, the method further comprising the step of determining a time difference between the user equipment and the receiver from the detected preamble.

127. A method as claimed in claim 126, wherein the time difference between the user equipment and the receiver comprises a delay introduced by the propagation of the signal from the user equipment to the receiver.

128. A method as claimed in any of claims 112 to 127, the method further comprising the step of determining a received power level at the receiver from the detected preamble.

129. A receiver for use in a communication system, the receiver comprising:

means for receiving a random access transmission from a user equipment, the random access transmission including a preamble, the random access transmission being formed to allow processing in the frequency domain;

means for processing the random access transmission in the frequency domain to detect the preamble.

130. A receiver as claimed in claim 129, wherein the means for receiving are adapted to receive a random access transmission in which the preamble has a first cyclic prefix.

131. A receiver as claimed in claim 129, wherein the means for receiving are adapted to receive a random access transmission in which the preamble is preceded by a first plurality of zero-valued symbols.

132. A receiver as claimed in claim 131, wherein the means for receiving is further adapted to receive a random access transmission in which the preamble is followed by a second plurality of zero-valued symbols.

133. A receiver as claimed in either of claims 131 or 132, wherein the preamble has a length of N samples, and the means for processing is adapted to identify an N-sample long portion of the received random access transmission to process, the N-sample long window covering at least a part of the preamble;

and add any part of the preamble falling outside the N-sample long portion to the start of the N-sample long portion.

134. A receiver as claimed in any of claims 130, 131, 132 or 133, wherein the means for processing is adapted to apply a Fourier transform to a portion of the received random access transmission.

135. A receiver as claimed in claim 134 when dependent on claim 130, wherein the means for processing is further adapted to apply a respective Fourier transform to each of a plurality of portions of the received random access transmission.

136. A receiver as claimed in claim 135, wherein the plurality of portions of the received random access transmission partially overlap.

137. A receiver as claimed in claim 136, wherein the plurality of portions are offset from each other by an amount that corresponds to the difference between the length of the first cyclic prefix and the maximum delay spread of the radio channel over which the random access transmission was transmitted.

138. A receiver as claimed in claim 134, 135, 136 or 137, wherein the portion or portions have a length that is equal to the length of the preamble.

139. A receiver as claimed in any of claims 134 to 138, wherein the means for processing is adapted to calculate a conjugate complex Fourier transform of each of a plurality of preambles in a set of possible preambles;

and to multiply each of the calculated Fourier transformed preambles by the Fourier transformed portion or portions.

140. A receiver as claimed in claim 139, wherein the means for processing is adapted to calculate an inverse Fourier transform of each multiplication.

141. A receiver as claimed in claim 140, wherein the means for processing is adapted to compare the results of the calculating an inverse Fourier transform step with a threshold to determine which of the preambles was used in the random access transmission.

142. A receiver as claimed in any of claims 134 to 141, wherein the means for processing is adapted to extract the frequency band used to transmit the random access transmission from the Fourier transformed portion of the received random access transmission.

143. A receiver as claimed in any of claims 129 to 142, the receiver further comprising means for determining a time difference between the user equipment and the receiver from the detected preamble.

144. A receiver as claimed in claim 143, wherein the time difference between the user equipment and the receiver comprises a delay introduced by the propagation of the signal from the user equipment to the receiver.

145. A receiver as claimed in any of claims 129 to 144, the receiver further comprising means for determining a received power level at the receiver from the detected preamble.

146. A random access transmission data structure for use by a device in accessing a communication system, the data structure comprising a preamble and being suitable for processing by a receiver in the frequency domain.

147. A random access transmission data structure as claimed in claim 146, in which the preamble has a first cyclic prefix.

148. A random access transmission data structure as claimed in claim 147, wherein the first cyclic prefix has a length that is at least equal to the maximum round trip delay for signals between the device and the receiver.

149. A random access transmission data structure as claimed in claim 148, wherein the first cyclic prefix has a length that is at least equal to the maximum round trip delay for signals between the device and the receiver plus the maximum delay spread of the channel between the device and the receiver.

150. A random access transmission data structure as claimed in claim 147, 148 or 149, wherein the trail of the preamble comprises a known training sequence.

151. A random access transmission data structure as claimed in claim 150, wherein at least a portion of the first cyclic prefix comprises a repeat of the known training sequence.

152. A random access transmission data structure as claimed in claim 147, 148, 149, 150 or 151, further comprising a message block.

153. A random access transmission data structure as claimed in claim 152, wherein the message block has a second cyclic prefix.

154. A random access transmission data structure as claimed in claim 153, wherein the second cyclic prefix is shorter than the first cyclic prefix.

155. A random access transmission data structure as claimed in claim 154, wherein the second cyclic prefix has a length that is at least equal to the maximum delay spread of the channel between the user equipment and the receiver.

156. A random access transmission data structure as claimed in claim 153, 154 or 155, wherein the message block ends with a known training sequence.

157. A random access transmission data structure as claimed in claim 156, wherein the length of the second cyclic prefix is such that the second cyclic prefix preceding the message block corresponds to the known training sequence.

158. A random access transmission data structure as claimed in any of claims 153, 154, 155, 156 or 157 when dependent on claims 147, 148 or 149, wherein the second cyclic prefix before the message block is considered to be a part of the preamble, and thus forms a portion of the first cyclic prefix.

159. A random access transmission data structure as claimed in claim 146, wherein the preamble is preceded by a first plurality of zero-valued symbols.

160. A random access transmission data structure as claimed in claim 159, wherein the preamble is followed by a second plurality of zero-valued symbols.

161. A random access transmission data structure as claimed in claim 159 or 160, further comprising a message block.

162. A random access transmission data structure as claimed in claim 161, wherein the message block precedes the preamble.

163. A random access transmission data structure as claimed in claim 162, wherein the message block is preceded by a third plurality of zero-valued symbols.

164. A random access transmission data structure as claimed in claim 162, wherein the message block has a second cyclic prefix.

165. A random access transmission data structure as claimed in claim 161, wherein the message block follows the preamble.

166. A random access transmission data structure as claimed in claim 165, wherein the message block is followed by a third plurality of zero-valued symbols.