System and method for Faster-than-Nyquist (FTN) transmission

Patent metadata

Field	Value
Publication number	US-10135540-B2
Application number	US-201715485272-A
Country	US
Kind code	B2
Filing date	Apr 12, 2017
Priority date	Apr 13, 2016
Publication date	Nov 20, 2018
Grant date	Nov 20, 2018

Abstract

Systems and methods are disclosed that attempt to increase spectral efficiency by using Faster-than-Nyquist (FTN) transmission. In one embodiment, a method at a transmitter includes partitioning bits into K bit streams, obtaining K power scaled symbol streams, combining the K power scaled symbol streams to obtain a stream of transmission symbols, and transmitting the stream of transmission symbols using FTN signaling. At the receiver, the received symbols are partitioned into K symbol streams, and demodulation and decoding is performed by: (i) demodulating and decoding the Kth symbol stream of the K symbol streams to obtain a Kth set of bits; (ii) mapping the Kth set of bits to a Kth set of symbols; and (iii) for each one of k=K−1, . . . , 1: demodulating and decoding a kth symbol stream of the K symbol streams to obtain a kth set of bits. The demodulating and decoding includes performing interference cancellation.

First claim

The invention claimed is:

1. A method performed at a transmitter comprising:
partitioning a plurality of bits into K bit streams;
obtaining K power scaled symbol streams by, for each one of k=1, . . . K:
encoding a k th bit stream of the K bit streams using a respective forward error correction encoder to obtain a k th encoded bit stream, mapping the k th encoded bit stream to respective symbols to obtain a k th symbol stream, and applying a respective power factor to the k th symbol stream to obtain a k th power scaled symbol stream;

combining the K power scaled symbol streams to obtain a stream of transmission symbols; and
transmitting the stream of transmission symbols using Faster-than-Nyquist (FTN) signaling;
wherein for each one of k=2, . . ., K: the respective power factor applied to the k th symbol stream satisfies the relationship

P
k

≥

ρ
⁡

(

σ
2

+

∑

i
=
1

k
-
1

⁢

⁢

∑

m
=

-
∞

m
=
∞

⁢

⁢



g
⁡

[

mK
+
i

]



2

⁢

P

k
-
i

)



g
⁡

[
0
]



2

⁢

(

1
+
ρ

)

-

ρ
⁢

∑

m
=

-
∞

m
=
∞

⁢

⁢



g
⁡

[
mK
]



2

where P k is the respective power factor of the k th symbol stream, ρ is a signal-to-interference-plus-noise ratio at which an error control code achieves error-free performance, σ 2 is noise variance of a channel, and g[n]=∫ −∞ ∞ h(t)h(t −nτT) dt, where τ is a time acceleration factor of the FTN signaling, h(t) is a transmit pulse, and T is a duration of the transmit pulse.

2. The method of claim 1 , wherein the respective power factor applied to one of the symbol streams has a magnitude larger than a magnitude of the respective power factor applied to another one of the symbol streams.

3. The method of claim 2 , wherein for each one of k=2, . . ., K:
the respective power factor applied to the k th symbol stream has a magnitude no less than a magnitude of the respective power factor applied to the (k−1) th symbol stream.

4. The method of claim 1 , wherein K is a function of bit error rate (BER) performance and peak-to-average-power ratio (PAPR) performance for a given code rate and for a given time acceleration factor τ of the FTN signaling.

5. A transmitter comprising:
K branches, each branch of the K branches to receive a respective one of K bit streams, and each branch having a respective forward error correction encoder, a respective symbol mapper, and a respective power scaler;
the transmitter configured to obtain K power scaled symbol streams by, for each one of k=1, . . . K:
encoding a k th bit stream of the K bit streams using the respective forward error correction encoder of a k th branch to obtain a k th encoded bit stream; mapping the k th encoded bit stream to respective symbols using the respective symbol mapper of the k th branch to obtain a k th symbol stream; and applying a respective power factor to the k th symbol stream using the respective power scaler of the k th branch to obtain a k th power scaled symbol stream;
the transmitter further configured to combine the K power scaled symbol streams to obtain a stream of transmission symbols and transmit the stream of transmission symbols using Faster-than-Nyquist (FIN) signaling;
wherein for each one

Assignees

• Medra Ahmed Mohamed Ibrahim
• Mitra Jeebak
• Lampe Lutz Hans Joachim
• Huawei Tech Canada Co Ltd

Inventors

• Medra Ahmed Mohamed Ibrahim
• Mitra Jeebak
• Lampe Lutz Hans-Joachim

Classifications

• H04L25/03834

  using pulse shaping · CPC title

• H04J11/004

  using regenerative subtractive interference cancellation · CPC title

• H04B10/516 Primary

  Details of coding or modulation · CPC title