Dual carrier modulator for a multiband OFDM UWB transceiver

• US 7,512,185 B2
• Filed: 01/21/2005
• Issued: 03/31/2009
• Est. Priority Date: 03/08/2004
• Status: Active Grant

• Current Assignee: Intel Corporation
• Original Assignee: Infineon Technologies AG
• Inventors: Sharon, Eran, Litsyn, Simon, Erlich, Yossi
• Primary Examiner(s): Payne; David C
• Assistant Examiner(s): Bolourchi; Nader
• Application Number:
  US11/040,475
• Publication Number:
  US 20050195765A1
• Time in Patent Office: 1,530 Days
• Field of Search: 375/260
• US Class Current: 375/260
• CPC Class Codes: H04B 1/7176 Data mapping, e.g. modulation
• CPC Class Codes: H04L 27/3405 Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power
• CPC Class Codes: H04L 5/0044 allocation of payload

Abstract

A Dual Carrier Modulator (DCM) for a Multiband OFDM (Orthogonal Frequency Division Multiplexing) Transceiver of a Ultra Wide Band (UWB) wireless personal access network transmitting OFDM modulated symbols is provided, wherein each OFDM symbol is modulated by a predetermined number of encoded bits. The Dual Carrier Modulator comprises a grouping unit for grouping N_CBPS encoded bits of a serial bit stream into bit groups each having a predetermined number of bits. The Dual Carrier Modulator also comprises a mapping unit for mapping each bit group received from said grouping unit to complex symbols using an orthogonal transform. The Dual Carrier Modulator further comprises a reordering unit for reordering the complex symbols mapped by said mapping unit. Each complex symbol is provided to modulate a corresponding data tone of an OFDM symbol.

Claims

1. A dual carrier modulator (DCM) for a multiband orthogonal frequency division multiplexing (OFDM) transceiver of an ultra wide band (UWB) wireless network transmitting OFDM modulated symbols, wherein each OFDM symbol is modulated by a first predetermined number (N_CBPS) of encoded bits, said dual carrier modulator comprising:

(a) a grouping unit configured to group the N_CBPS encoded bits of a serial bit stream into bit groups each having a second predetermined number (m) of bits;

(b) a mapping unit configured to map each bit group received from said grouping unit to complex symbols (y); and

(c) a reordering unit configured to reorder the complex symbols (y) mapped by said mapping unit, wherein each complex symbol (y) is provided to modulate a corresponding data tone of an OFDM symbol;

wherein the first predetermined number is two hundred (N_CBPS=200) and the second predetermined number is four (m =4), such that the grouping unit groups two hundred encoded bits to bit groups each having four bits;

wherein the mapping unit maps bit groups each having four bits respectively to two complex symbols (y_n;

y_n+NCBPS/4) to generate N_CBPS/2 complex symbols (y₀. . . y_NCBPS/2) for modulating one N_CBPS/2 data tones of an OFDM symbol;

wherein the mapping unit (1-2) comprises;

a first mapping stage for mapping unipolar bit values of the encoded bits within each bit group to bipolar bit values, and

a second mapping stage which provides an orthogonal 2×

2 mapping of two complex numbers composed of the 4 bipolar bits into two complex symbols; and

wherein the orthogonal 2×

2 mapping is defined by the equation;

2. The dual carrier modulator of claim 1, wherein the mapping unit is formed by a look-up-table stored in a memory.

3. The dual Carrier Modulator according to claim 1, wherein the look-up-table stored in said memory is given as follows:

4. The dual carrier modulator of claim 3, wherein the constant b is two (b=2).

5. The dual carrier modulator of claim 1, wherein the constant b is two(b=2).