Methods and apparatus for communicating a single carrier waveform
AssigneeHuawei Technologies Co., Ltd.
InventorsNUWAN SURESH FERDINAND, MING JIA, JIANGLEI MA
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Abstract
Aspects of the present application provide methods and devices for time domain implementation of a single carrier waveform such as single carrier quadrature amplitude modulation (QAM) DFT-s-OFDM and single carrier Offset QAM (OQAM). A time domain implementation allows flexible symbol lengths, lower implementation complexity as a large IDFT operation is not required in the time domain and support for variable cyclic prefix (CP) length. An OQAM implementation utilizes a pre-processing step to convert a K complex QAM symbol sequence into a 2K OQAM symbol sequence and generates a sequence for transmission in the time domain as opposed to the frequency domain.
Claims24
A method comprising:
- generating M Offset QAM (OQAM) symbols, M=2K, wherein K is a number of quadrature amplitude modulation (QAM) symbols;
- obtaining, in the time domain, a single carrier waveform based on M OQAM symbols by:
- upsampling the M OQAM symbols to generate N upsampled OQAM symbols;
- and
- pulse shaping the N upsampled OQAM symbols by convolving the N upsampled OQAM symbols with a square root Nyquist pulse having a length equal to L.
A method comprising:
- receiving a signal including N upsampled offset OQAM;
- match filtering the received signal by using a combined version of an impulse response of a communication channel and a square root Nyquist pulse that is complementary to a square root Nyquist pulse used for pulse shaping at a transmitter;
- and
- down-sampling the N upsampled OQAM symbols to generate 2K OQAM symbols;
- and
- generating K QAM symbols from the 2K OQAM symbols.
A device comprising:
- a processor;
- and
- a computer-readable medium having stored thereon computer executable instructions, that when executed by the processor, cause the device to:
- generate M Offset QAM (OQAM) symbols, M=2K, wherein K is a number of quadrature amplitude modulation (QAM) symbols;
- obtain, in the time domain, a single carrier waveform based on M OQAM symbols by:
- upsampling the M OQAM symbols to generate N upsampled OQAM symbols;
- and
- pulse shaping the N upsampled OQAM symbols by convolving the N upsampled OQAM symbols with a square root Nyquist pulse having a length equal to L.
A device comprising:
- a processor;
- and
- a computer-readable medium having stored thereon computer executable instructions, that when executed by the processor, cause the device to:
- receive a signal including N upsampled offset OQAM;
- match filter the received signal by using a combined version of an impulse response of a communication channel and a square root Nyquist pulse that is complementary to a square root Nyquist pulse used for pulse shaping at a transmitter;
- and
- down-sample the N upsampled OQAM symbols to generate 2K OQAM symbols;
- and
- generate K QAM symbols from the 2K OQAM symbols.
Dependencies are inferred from the claim text.