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US 8,787,143 B2Granted
Method and apparatus for hybrid FDM-CDM structure for single carrier based control channels
AssigneeQUALCOMM Incorporated
InventorDurga Prasad Malladi
Life of this patent
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Abstract
A system and method for hybrid FDM (frequency division multiplexing)-CDM (code division multiplexing) structure for single carrier control channels is provided. The hybrid FDM-CDM structure maximizes frequency diversity over the entire available bandwidth such that orthogonality between signals from users in a given cell is maintained. Thus, users in the given cell can transmit over a non-contiguous set of tones. Furthermore, the hybrid FDM-CDM structure maintains orthogonality of a pilot of users in different cells based on a despreading operation in the time domain.
Claims46
An apparatus for wireless communication, comprising:
- means for spreading a signal from a first user in a first group of users across frequency, wherein signals from different users in the first group of users are code division multiplexed (CDM) in frequency domain;
- means for spreading the signal from the first user across time, wherein the signals from the different users in the first group of users are code division multiplexed in time domain;
- and
- means for mapping the signal from the first user to a first set of subcarriers assigned to the first group of users and corresponding to a subset of a plurality of subcarriers available for assignment to users, wherein signals from all users in the first group of users are sent on the first set of subcarriers, and wherein signals from different groups of users are frequency division multiplexed (FDM) and sent on different sets of subcarriers corresponding to different non-overlapping subsets of the plurality of subcarriers available for assignment to users.
1 more element
An apparatus for wireless communication, comprising:
- a generating component that spreads a signal from a first user in a first group of users across frequency, spreads the signal from the first user across time, and maps the signal from the first user to a first set of subcarriers assigned to the first group of users and corresponding to a subset of a plurality of subcarriers available for assignment to users, wherein signals from different users in the first group of users are code division multiplexed (CDM) in frequency domain and time domain, wherein signals from all users in the first group of users are sent on the first set of subcarriers, and wherein signals from different groups of users are frequency division multiplexed (FDM) and sent on different sets of subcarriers corresponding to different non-overlapping subsets of the plurality of subcarriers available for assignment to users.
A method for wireless communication, comprising:
- spreading a signal from a first user in a first group of users across frequency, wherein signals from different users in the first group of users are code division multiplexed (CDM) in frequency domain;
- spreading the signal from the first user across time, wherein the signals from the different users in the first group of users are code division multiplexed in time domain;
- and
- mapping the signal from the first user to a first set of subcarriers assigned to the first group of users and corresponding to a subset of a plurality of subcarriers available for assignment to users, wherein signals from all users in the first group of users are sent on the first set of subcarriers, and wherein signals from different groups of users are frequency division multiplexed (FDM) and sent on different sets of subcarriers corresponding to different non-overlapping subsets of the plurality of subcarriers available for assignment to users.
1 more element
An apparatus for wireless communication, comprising:
- a receiving component that obtains a received signal comprising a signal from a first user in a first group of users, the signal from the first user being spread across frequency and time and further mapped to a first set of subcarriers assigned to the first group of users and corresponding to a subset of a plurality of subcarriers available for assignment to users, wherein signals from different users in the first group of users are code division multiplexed in frequency domain and time domain, wherein signals from all users in the first group of users are sent on the first set of subcarriers, and wherein signals from different groups of users are frequency division multiplexed and sent on different sets of subcarriers corresponding to different non-overlapping subsets of the plurality of subcarriers available for assignment to users.
A method for wireless communication, comprising:
- obtaining a received signal comprising a signal from a first user in a first group of users, the signal from the first user being spread across frequency and time and further mapped to a first set of subcarriers assigned to the first group of users and corresponding to a subset of a plurality of subcarriers available for assignment to users, wherein signals from different users in the first group of users are code division multiplexed in frequency domain and time domain, wherein signals from all users in the first group of users are sent on the first set of subcarriers, and wherein signals from different groups of users are frequency division multiplexed and sent on different sets of subcarriers corresponding to different non-overlapping subsets of the plurality of subcarriers available for assignment to users;
- demodulating the received signal to obtain a demodulated signal;
- and
- despreading the demodulated signal in time domain and frequency domain to recover the signal from the first user.
1 more element
A wireless communications apparatus, comprising:
- means for obtaining a received signal comprising a signal from a first user in a first group of users, the signal from the first user being spread across frequency and time and further mapped to a first set of subcarriers assigned to the first group of users and corresponding to a subset of a plurality of subcarriers available for assignment to users, wherein signals from different users in the first group of users are code division multiplexed in frequency domain and time domain, wherein signals from all users in the first group of users are sent on the first set of subcarriers, and wherein signals from different groups of users are frequency division multiplexed and sent on different sets of subcarriers corresponding to different non-overlapping subsets of the plurality of subcarriers available for assignment to users;
- means for demodulating the received signal to obtain a demodulated signal;
- and
- means for despreading the demodulated signal in time domain and frequency domain to recover the signal from the first user.
1 more element
A method for wireless communication, comprising:
- identifying a set of signals from users in at least one cell based in part on demodulation of a received signal, wherein a signal from each of the users is spread across frequency and time, wherein the set of signals from the users is code division multiplexed in frequency domain and time domain and is sent on a set of subcarriers corresponding to a subset of a plurality of subcarriers available for assignment to users, wherein the set of signals from the users is frequency division multiplexed with at least one other set of signals from other users in the at least one cell, and wherein the set of signals and the at least one other set of signals are sent on different sets of subcarriers corresponding to different non-overlapping subsets of the plurality of subcarriers available for assignment to users;
- and
- identifying at least one signal associated with a specific user in the at least one cell based in part on a despreading operation performed on a demodulated signal in time domain and frequency domain.
A non-transitory processor-readable medium including instructions stored thereon, comprising:
- instructions for spreading a signal from a first user in a first group of users across frequency;
- instructions for spreading the signal from the first user across time;
- and
- instructions for mapping the signal from the first user to a first set of subcarriers assigned to the first group of users and corresponding to a subset of a plurality of subcarriers available for assignment to users, wherein signals from different users in the first group of users are code division multiplexed in frequency domain and time domain, wherein signals from all users in the first group of users are sent on the first set of subcarriers, and wherein signals from different groups of users are frequency division multiplexed and sent on different sets of subcarriers corresponding to different non-overlapping subsets of the plurality of subcarriers available for assignment to users.
1 more element
An apparatus for wireless communication, comprising:
- a processor configured to:
- spread a signal from a first user in a first group of users across frequency,
- spread the signal from the first user across time, and
- map the signal from the first user to a first set of subcarriers assigned to the first group of users and corresponding to a subset of a plurality of subcarriers available ibr assignment to users, wherein signals from different users in the first group of users are code division multiplexed in frequency domain and time domain, wherein signals from all users in the first group of users are sent on the first set of subcarriers, and wherein signals from different groups of users are frequency division multiplexed and sent on different sets of subcarriers corresponding to different non-overlapping subsets of the plurality of subcarriers available for assignment to users.
1 more element
A wireless communications apparatus, comprising:
- a memory that retains instructions related to obtaining a received signal comprising a signal from a first user in a first group of users, the signal from the first user being spread across frequency and time and further mapped to a first set of subcarriers assigned to the first group of users and corresponding to a subset of a plurality of subcarriers available for assignment to users, wherein signals from different users in the first group of users are code division multiplexed in frequency domain and time domain, wherein signals from all users in the first group of users are sent on the first set of subcarriers, and wherein signals from different groups of users are frequency division multiplexed and sent on different sets of subcarriers corresponding to different non-overlapping subsets of the plurality of subcarriers available for assignment to users;
- and
- a processor coupled to the memory, configured to execute the instructions retained in the memory.
Dependencies are inferred from the claim text.