Random access cyclic prefix dimensioning in wireless networks
AssigneeTexas Instruments Incorporated
InventorsPierre Bertrand, Srinivasa Raghavan Sridhara
Life of this patent
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Abstract
User equipment (UE)-initiated accesses within a cellular network include non-synchronized random access requests when the UE is not synchronized with a base station that is serving a cell occupied by the UE. The random access request is formed by generating a set of samples at a selected sample rate, such that the set of samples spans a specified duration period, wherein the sample rate is one of a plurality of different sample rates enabling different implementations of the random access transmission. The specified duration period is integrally divisible by each of the plurality of different sample periods.
Claims19
A method for transmitting in a wireless network, comprising:
- generating an OFDM symbol along with its cyclic prefix (CP) at a selected sample period, such that both the OFDM symbol and the CP span specified duration periods TSYM and TCP respectively, wherein the selected sample period is one of a plurality of different sample periods;
- and
- wherein the plurality of said sample periods enables both full frequency domain and hybrid time-frequency domain generation of both the OFDM symbol and the CP;
- and
- wherein both the specified duration periods TSYM and TCP are integrally divisible by each of the plurality of different sample periods.
A method for transmitting from user equipment (UE) to base stations (nodeB) in a cellular network, comprising:
- establishing a fixed set of preamble parameter configurations for use across a complete range of cell sizes within the cellular network;
- receiving at a UE located in a cell a configuration ID transmitted from a nodeB serving the cell, the configuration ID being indicative of a size of the cell;
- selecting a preamble parameter configuration specified by the received configuration ID from the fixed set of preamble parameter configurations, wherein the preamble parameter configuration specifies a selected duration period for a cyclic prefix that is integrally divisible by each of a plurality of different sample periods;
- wherein the plurality of said sample periods enables both full frequency domain and hybrid time-frequency domain generation of the preamble and its cyclic prefix;
- wherein the smaller sample period TS of the plurality of sample periods is the system sampling period;
- generating a preamble sequence and a cyclic prefix using the preamble parameter configuration indicated by the configuration ID and using one of the plurality of different sample periods;
- and
- transmitting the preamble and cyclic prefix from the UE to the nodeB.
A method for transmitting in a wireless network, comprising:
- receiving a random access request burst on a physical random access channel comprising a preamble and an appended cyclic prefix;
- removing the cyclic prefix, wherein the cyclic prefix has a specified duration period that is integrally divisible by each of a plurality of different sample periods;
- wherein the smaller sample period TS of the plurality of sample periods is the system sampling period;
- and
- detecting the remaining preamble.
A user apparatus (UE) for use in a cellular wireless network, comprising:
- a receiver connected to an antenna operable to receive information within a given cell that designates a particular configuration ID of a fixed set of preamble parameter configurations for use across a complete range of cell sizes within the cellular network;
- a processor connected to a storage memory holding instructions for execution by the processor and for holding the fixed set of preamble parameter configurations and connected to obtain signals from the receiver, wherein the processor is operable to select a preamble parameter configuration specified by the received configuration ID from the fixed set of preamble parameter configurations, wherein the preamble parameter configuration specifies a selected duration period for a cyclic prefix that is integrally divisible by each of a plurality of different sample periods;
- wherein the plurality of said sample periods enables both full frequency domain and hybrid time-frequency domain generation of the preamble and its cyclic prefix;
- wherein the smaller sample period TS of the plurality of sample periods is the system sampling period;
- a transmitter coupled to the storage memory operable to generate a random access burst having a preamble sequence and a cyclic prefix having a selected duration period using the preamble parameter configuration indicated by the configuration ID and using one of the plurality of different sample periods;
- and
- the transmitter being operable to transmit the generated random access burst from the cellular telephone to the NodeB.
Dependencies are inferred from the claim text.